Biotechnology for Biofuels最新文献

{"title":"Simultaneous fermentation and enzymatic biocatalysis—a useful process option?","authors":"Katharina Oehlenschläger,&nbsp;Emily Schepp,&nbsp;Judith Stiefelmaier,&nbsp;Dirk Holtmann,&nbsp;Roland Ulber","doi":"10.1186/s13068-024-02519-z","DOIUrl":"10.1186/s13068-024-02519-z","url":null,"abstract":"<div><p>Biotransformation with enzymes and de novo syntheses with whole-cell biocatalysts each have specific advantages. These can be combined to achieve processes with optimal performance. A recent approach is to perform bioconversion processes and enzymatic catalysis simultaneously in one-pot. This is a well-established process in the biorefinery, where starchy or cellulosic material is degraded enzymatically and simultaneously used as substrate for microbial cultivations. This procedure leads to a number of advantages like saving in time but also in the needed equipment (e.g., reaction vessels). In addition, the inhibition or side-reaction of high sugar concentrations can be overcome by combining the processes. These benefits of coupling microbial conversion and enzymatic biotransformation can also be transferred to other processes for example in the sector of biofuel production or in the food industry. However, finding a compromise between the different requirements of the two processes is challenging in some cases. This article summarises the latest developments and process variations.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"17 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-024-02519-z","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141097939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved biological methanation using tubular foam-bed reactor","authors":"Hoda Khesali Aghtaei,&nbsp;Robert Heyer,&nbsp;Udo Reichl,&nbsp;Dirk Benndorf","doi":"10.1186/s13068-024-02509-1","DOIUrl":"10.1186/s13068-024-02509-1","url":null,"abstract":"<div><h3>Background</h3><p>Power-to-gas is the pivotal link between electricity and gas infrastructure, enabling the broader integration of renewable energy. Yet, enhancements are necessary for its full potential. In the biomethanation process, transferring H₂ into the liquid phase is a rate-limiting step. To address this, we developed a novel tubular foam-bed reactor (TFBR) and investigated its performance at laboratory scale.</p><h3>Results</h3><p>A non-ionic polymeric surfactant (Pluronic^® F-68) at 1.5% w/v was added to the TFBR’s culture medium to generate a stabilized liquid foam structure. This increased both the gas–liquid surface area and the bubble retention time. Within the tubing, cells predominantly traveled evenly suspended in the liquid phase or were entrapped in the thin liquid film of bubbles flowing inside the tube. Phase (I) of the experiment focused primarily on mesophilic (40 °C) operation of the tubular reactor, followed by phase (II), when Pluronic^® F-68 was added. In phase (II), the TFBR exhibited 6.5-fold increase in biomethane production rate (<i>MPR</i>) to 15.1 <span>(({text{L}}_{{text{CH}}_{4}}text{/}{text{L}}_{text{R}}text{/d)})</span>, with a CH₄ concentration exceeding 90% (grid quality), suggesting improved H₂ transfer. Transitioning to phase (III) with continuous operation at 55 °C, the <i>MPR</i> reached 29.7 <span>({text{L}}_{{text{CH}}_{4}}text{/}{text{L}}_{text{R}}text{/d})</span> while maintaining the grid quality CH₄. Despite, reduced gas–liquid solubility and gas–liquid mass transfer at higher temperatures, the twofold increase in <i>MPR</i> compared to phase (II) might be attributed to other factors, i.e., higher metabolic activity of the methanogenic archaea.</p><p>To assess process robustness for phase (II) conditions, a partial H₂ feeding regime (12 h 100% and 12 h 10% of the nominal feeding rate) was implemented. Results demonstrated a resilient <i>MPR</i> of approximately 14.8 <span>({text{L}}_{{text{CH}}_{4}}text{/}{text{L}}_{text{R}}text{/d})</span> even with intermittent, low H₂ concentration.</p><h3>Conclusions</h3><p>Overall, the TFBR’s performance plant sets the course for an accelerated introduction of biomethanation technology for the storage of volatile renewable energy. Robust process performance, even under H₂ starvation, underscores its reliability. Further steps towards an optimum operation regime and scale-up should be initiated. Additionally, the use of TFBR systems should be considered for biotechnological processes in which gas–liquid mass transfer is a limiting factor for achieving higher reaction rates.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"17 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-024-02509-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140941272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Engineering non-conventional yeast Rhodotorula toruloides for ergothioneine production","authors":"Ke Liu,&nbsp;Gedan Xiang,&nbsp;Lekai Li,&nbsp;Tao Liu,&nbsp;Jie Ke,&nbsp;Liangbin Xiong,&nbsp;Dongzhi Wei,&nbsp;Fengqing Wang","doi":"10.1186/s13068-024-02516-2","DOIUrl":"10.1186/s13068-024-02516-2","url":null,"abstract":"<div><h3>Background</h3><p>Ergothioneine (EGT) is a distinctive sulfur-containing histidine derivative, which has been recognized as a high-value antioxidant and cytoprotectant, and has a wide range of applications in food, medical, and cosmetic fields. Currently, microbial fermentation is a promising method to produce EGT as its advantages of green environmental protection, mild fermentation condition, and low production cost. However, due to the low-efficiency biosynthetic process in numerous cell factories, it is still a challenge to realize the industrial biopreparation of EGT. The non-conventional yeast <i>Rhodotorula toruloides</i> is considered as a potential candidate for EGT production, thanks to its safety for animals and natural ability to synthesize EGT. Nevertheless, its synthesis efficiency of EGT deserves further improvement.</p><h3>Results</h3><p>In this study, out of five target wild-type <i>R. toruloides</i> strains, <i>R. toruloides</i> 2.1389 (RT1389) was found to accumulate the highest EGT production, which could reach 79.0 mg/L at the shake flask level on the 7th day. To achieve iterative genome editing in strain RT1389, CRISPR-assisted Cre recombination (CACR) method was established. Based on it, an EGT-overproducing strain RT1389-2 was constructed by integrating an additional copy of EGT biosynthetic core genes <i>RtEGT1</i> and <i>RtEGT2</i> into the genome, the EGT titer of which was 1.5-fold increase over RT1389. As the supply of S-adenosylmethionine was identified as a key factor determining EGT production in strain RT1389, subsequently, a series of gene modifications including S-adenosylmethionine rebalancing were integrated into the strain RT1389-2, and the resulting mutants were rapidly screened according to their EGT production titers with a high-throughput screening method based on ergothionase. As a result, an engineered strain named as RT1389-3 was selected with a production titer of 267.4 mg/L EGT after 168 h in a 50 mL modified fermentation medium.</p><h3>Conclusions</h3><p>This study characterized the EGT production capacity of these engineered strains, and demonstrated that CACR and high-throughput screening method allowed rapid engineering of <i>R. toruloides</i> mutants with improved EGT production. Furthermore, this study provided an engineered RT1389-3 strain with remarkable EGT production performance, which had potential industrial application prospects.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"17 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-024-02516-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140914584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal trade-off between boosted tolerance and growth fitness during adaptive evolution of yeast to ethanol shocks","authors":"Ana Paula Jacobus,&nbsp;Stella Diogo Cavassana,&nbsp;Isabelle Inácio de Oliveira,&nbsp;Joneclei Alves Barreto,&nbsp;Ewerton Rohwedder,&nbsp;Jeverson Frazzon,&nbsp;Thalita Peixoto Basso,&nbsp;Luiz Carlos Basso,&nbsp;Jeferson Gross","doi":"10.1186/s13068-024-02503-7","DOIUrl":"10.1186/s13068-024-02503-7","url":null,"abstract":"<div><h3>Background</h3><p>The selection of <i>Saccharomyces cerevisiae</i> strains with higher alcohol tolerance can potentially increase the industrial production of ethanol fuel. However, the design of selection protocols to obtain bioethanol yeasts with higher alcohol tolerance poses the challenge of improving industrial strains that are already robust to high ethanol levels. Furthermore, yeasts subjected to mutagenesis and selection, or laboratory evolution, often present adaptation trade-offs wherein higher stress tolerance is attained at the expense of growth and fermentation performance. Although these undesirable side effects are often associated with acute selection regimes, the utility of using harsh ethanol treatments to obtain robust ethanologenic yeasts still has not been fully investigated.</p><h3>Results</h3><p>We conducted an adaptive laboratory evolution by challenging four populations (P1–P4) of the Brazilian bioethanol yeast, <i>Saccharomyces cerevisiae</i> PE-2_H4, through 68–82 cycles of 2-h ethanol shocks (19–30% v/v) and outgrowths. Colonies isolated from the final evolved populations (P1c–P4c) were subjected to whole-genome sequencing, revealing mutations in genes enriched for the cAMP/PKA and trehalose degradation pathways. Fitness analyses of the isolated clones P1c–P3c and reverse-engineered strains demonstrated that mutations were primarily selected for cell viability under ethanol stress, at the cost of decreased growth rates in cultures with or without ethanol. Under this selection regime for stress survival, the population P4 evolved a protective snowflake phenotype resulting from <i>BUD3</i> disruption. Despite marked adaptation trade-offs, the combination of reverse-engineered mutations <i>cyr1</i>^{<i>A1474T</i>}/<i>usv1Δ</i> conferred 5.46% higher fitness than the parental PE-2_H4 for propagation in 8% (v/v) ethanol, with only a 1.07% fitness cost in a culture medium without alcohol. The <i>cyr1</i>^{<i>A1474T</i>}/<i>usv1Δ</i> strain and evolved P1c displayed robust fermentations of sugarcane molasses using cell recycling and sulfuric acid treatments, mimicking Brazilian bioethanol production.</p><h3>Conclusions</h3><p>Our study combined genomic, mutational, and fitness analyses to understand the genetic underpinnings of yeast evolution to ethanol shocks. Although fitness analyses revealed that most evolved mutations impose a cost for cell propagation, combination of key mutations <i>cyr1</i>^{<i>A1474T</i>}/<i>usv1Δ</i> endowed yeasts with higher tolerance for growth in the presence of ethanol. Moreover, alleles selected for acute stress survival comprising the P1c genotype conferred stress tolerance and optimal performance under conditions simulating the Brazilian industrial ethanol production.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"17 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-024-02503-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140904617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A bioprocess engineering approach for the production of hydrocarbons and fatty acids from green microalga under high cobalt concentration as the feedstock of high-grade biofuels","authors":"Alok Patel,&nbsp;Chloe Rantzos,&nbsp;Eleni Krikigianni,&nbsp;Ulrika Rova,&nbsp;Paul Christakopoulos,&nbsp;Leonidas Matsakas","doi":"10.1186/s13068-024-02512-6","DOIUrl":"10.1186/s13068-024-02512-6","url":null,"abstract":"<div><p><i>Botryococcus braunii</i>, a colonial green microalga which is well-known for its capacity to synthesize hydrocarbons, has significant promise as a long-term source of feedstock for the generation of biofuels. However, cultivating and scaling up <i>B. braunii</i> using conventional aqua-suspended cultivation systems remains a challenge. In this study, we optimized medium components and light intensity to enhance lipid and hydrocarbon production in a multi-cultivator airlift photobioreactor. BBM 3N medium with 200 μmol/m²/s light intensity and a 16 h light–8 h dark regimen yielded the highest biomass productivity (110.00 ± 2.88 mg/L/day), as well as the highest lipid and hydrocarbon content. Cultivation in a flat-panel bioreactor resulted in significantly higher biomass productivity (129.11 ± 2.74 mg/L/day), lipid productivity (32.21 ± 1.31 mg/L/day), and hydrocarbon productivity (28.98 ± 2.08 mg/L/day) compared to cultivation in Erlenmeyer flasks and open 20-L raceway pond. It also exhibited 20.15 ± 1.03% of protein content including elevated levels of chlorophyll <i>a</i>, chlorophyll <i>b</i>, and carotenoids. This work is noteworthy since it is the first to describe fatty acid and hydrocarbon profiles of <i>B. braunii</i> during cobalt treatment. The study demonstrated that high cobalt concentrations (up to 5 mg/L of cobalt nitrate) during <i>Botryococcus</i> culture affected hydrocarbon synthesis, resulting in high amounts of <i>n</i>-alkadienes and trienes as well as lipids with elevated monounsaturated fatty acids concentration. Furthermore, pyrolysis experiments on microalgal green biomass and de-oiled biomass revealed the lipid and hydrocarbon compounds generated by the thermal degradation of <i>B. braunii</i> that facilitate extra economical value to this system.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"17 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-024-02512-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140904615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid fractionation of corn stover by microwave-assisted protic ionic liquid [TEA][HSO4] for fermentative acetone–butanol–ethanol production","authors":"Yankun Wang,&nbsp;Di Cai,&nbsp;Yongjie Jiang,&nbsp;Xueying Mei,&nbsp;Wenqiang Ren,&nbsp;Mingyuan Sun,&nbsp;Changsheng Su,&nbsp;Hui Cao,&nbsp;Changwei Zhang,&nbsp;Peiyong Qin","doi":"10.1186/s13068-024-02499-0","DOIUrl":"10.1186/s13068-024-02499-0","url":null,"abstract":"<div><h3>Background</h3><p>The use of ionic liquids (ILs) to fractionate lignocelluloses for various bio-based chemicals productions is in the ascendant. On this basis, the protic ILs consisting of triethylammonium hydrogen sulfate ([TEA][HSO₄]) possessed great promise due to the low price, low pollution, and high efficiency. In this study, the microwave-assistant [TEA][HSO₄] fractionation process was established for corn stover fractionation, so as to facilitate the monomeric sugars production and supported the downstream acetone–butanol–ethanol (ABE) fermentation.</p><h3>Results</h3><p>The assistance of microwave irradiation could obviously shorten the fractionation period of corn stover. Under the optimized condition (190 W for 3 min), high xylan removal (93.17 ± 0.63%) and delignification rate (72.90 ± 0.81%) were realized. The mechanisms for the promotion effect of the microwave to the protic ILs fractionation process were ascribed to the synergistic effect of the IL and microwaves to the depolymerization of lignocellulose through the ionic conduction, which can be clarified by the characterization of the pulps and the isolated lignin specimens. Downstream valorization of the fractionated pulps into ABE productions was also investigated. The [TEA][HSO₄] free corn stover hydrolysate was capable of producing 12.58 g L⁻¹ of ABE from overall 38.20 g L⁻¹ of monomeric sugars without detoxification and additional nutrients supplementation.</p><h3>Conclusions</h3><p>The assistance of microwave irradiation could significantly promote the corn stover fractionation by [TEA][HSO₄]. Mass balance indicated that 8.1 g of ABE and 16.61 g of technical lignin can be generated from 100 g of raw corn stover based on the novel fractionation strategy.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"17 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-024-02499-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140878119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced upgrading of lignocellulosic substrates by coculture of Saccharomyces cerevisiae and Acinetobacter baylyi ADP1","authors":"Changshuo Liu,&nbsp;Bohyun Choi,&nbsp;Elena Efimova,&nbsp;Yvonne Nygård,&nbsp;Suvi Santala","doi":"10.1186/s13068-024-02510-8","DOIUrl":"10.1186/s13068-024-02510-8","url":null,"abstract":"<div><h3>Background</h3><p>Lignocellulosic biomass as feedstock has a huge potential for biochemical production. Still, efficient utilization of hydrolysates derived from lignocellulose is challenged by their complex and heterogeneous composition and the presence of inhibitory compounds, such as furan aldehydes. Using microbial consortia where two specialized microbes complement each other could serve as a potential approach to improve the efficiency of lignocellulosic biomass upgrading.</p><h3>Results</h3><p>This study describes the simultaneous inhibitor detoxification and production of lactic acid and wax esters from a synthetic lignocellulosic hydrolysate by a defined coculture of engineered <i>Saccharomyces cerevisiae</i> and <i>Acinetobacter baylyi</i> ADP1. <i>A. baylyi</i> ADP1 showed efficient bioconversion of furan aldehydes present in the hydrolysate, namely furfural and 5-hydroxymethylfurfural, and did not compete for substrates with <i>S. cerevisiae</i>, highlighting its potential as a coculture partner. Furthermore, the remaining carbon sources and byproducts of <i>S. cerevisiae</i> were directed to wax ester production by <i>A. baylyi</i> ADP1. The lactic acid productivity of <i>S. cerevisiae</i> was improved approximately 1.5-fold (to 0.41 ± 0.08 g/L/h) in the coculture with <i>A. baylyi</i> ADP1, compared to a monoculture of <i>S. cerevisiae</i>.</p><h3>Conclusion</h3><p>The coculture of yeast and bacterium was shown to improve the consumption of lignocellulosic substrates and the productivity of lactic acid from a synthetic lignocellulosic hydrolysate. The high detoxification capacity and the ability to produce high-value products by <i>A. baylyi</i> ADP1 demonstrates the strain to be a potential candidate for coculture to increase production efficiency and economics of <i>S. cerevisiae</i> fermentations.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"17 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-024-02510-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140844582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular weight control of poly-γ-glutamic acid reveals novel insights into extracellular polymeric substance synthesis in Bacillus licheniformis","authors":"Xiaoyu Wei,&nbsp;Lijie Yang,&nbsp;Zhen Chen,&nbsp;Wenhao Xia,&nbsp;Yongbin Chen,&nbsp;Mingfeng Cao,&nbsp;Ning He","doi":"10.1186/s13068-024-02501-9","DOIUrl":"10.1186/s13068-024-02501-9","url":null,"abstract":"<div><h3>Background</h3><p>The structural diversity of extracellular polymeric substances produced by microorganisms is attracting particular attention. Poly-gamma-glutamic acid (γ-PGA) is a widely studied extracellular polymeric substance from <i>Bacillus</i> species. The function of γ-PGA varies with its molecular weight (Mw).</p><h3>Results</h3><p>Herein, different endogenous promoters in <i>Bacillus licheniformis</i> were selected to regulate the expression levels of <i>pgdS</i>, resulting in the formation of γ-PGA with Mw values ranging from 1.61 × 10³ to 2.03 × 10⁴ kDa. The yields of γ-PGA and exopolysaccharides (EPS) both increased in the <i>pgdS</i> engineered strain with the lowest Mw and viscosity, in which the EPS content was almost tenfold higher than that of the wild-type strain. Subsequently, the compositions of EPS from the <i>pgdS</i> engineered strain also changed. Metabolomics and RT-qPCR further revealed that improving the transportation efficiency of EPS and the regulation of carbon flow of monosaccharide synthesis could affect the EPS yield.</p><h3>Conclusions</h3><p>Here, we present a novel insight that increased <i>pgdS</i> expression led to the degradation of γ-PGA Mw and changes in EPS composition, thereby stimulating EPS and γ-PGA production. The results indicated a close relationship between γ-PGA and EPS in <i>B. licheniformis</i> and provided an effective strategy for the controlled synthesis of extracellular polymeric substances.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"17 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-024-02501-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140844570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Taurine-mediated gene transcription and cell membrane permeability reinforced co-production of bioethanol and Monascus azaphilone pigments for a newly isolated Monascus purpureus","authors":"Xia Yi,&nbsp;Jianqi Han,&nbsp;Xiaoyan Xu,&nbsp;Yilong Wang,&nbsp;Meng Zhang,&nbsp;Jie Zhu,&nbsp;Yucai He","doi":"10.1186/s13068-024-02511-7","DOIUrl":"10.1186/s13068-024-02511-7","url":null,"abstract":"<div><h3>Background</h3><p>Taurine, a semi-essential micronutrient, could be utilized as a sulfur source for some bacteria; however, little is known about its effect on the accumulation of fermentation products. Here, it investigated the effect of taurine on co-production of bioethanol and <u>Mon</u>ascus <u>az</u>aphilone <u>p</u>igment<u>s</u> (MonAzPs) for a fungus.</p><h3>Results</h3><p>A newly isolated fungus of 98.92% identity with <i>Monascus purpureus</i> co-produced 23.43 g/L bioethanol and 66.12, 78.01 and 62.37 U/mL red, yellow and orange MonAzPs for 3 d in synthetic medium (SM). Taurine enhanced bioethanol titer, ethanol productivity and ethanol yield at the maximum by 1.56, 1.58 and 1.60 times than those of the control in corn stover hydrolysates (CSH), and red, yellow and orange MonAzPs were raised by 1.24, 1.26 and 1.29 times, respectively. Taurine was consumed extremely small quantities for <i>M. purpureus</i> and its promotional effect was not universal for the other two biorefinery fermenting strains. Taurine intensified the gene transcription of glycolysis (glucokinase, phosphoglycerate mutase, enolase and alcohol dehydrogenase) and MonAzPs biosynthesis (serine hydrolases, C-11-ketoreductase, FAD-dependent monooxygenase, 4-<i>O</i>-acyltransferase, deacetylase, NAD(P)H-dependent oxidoredutase, FAD-dependent oxidoredutase, enoyl reductase and fatty acid synthase) through de novo RNA-Seq assays. Furthermore, taurine improved cell membrane permeability through changing cell membrane structure by microscopic imaging assays.</p><h3>Conclusions</h3><p>Taurine reinforced co-production of bioethanol and MonAzPs by increasing gene transcription level and cell membrane permeability for <i>M. purpureus</i>. This work would offer an innovative, efficient and taurine-based co-production system for mass accumulation of the value-added biofuels and biochemicals from lignocellulosic biomass.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"17 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-024-02511-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140820448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vanillin production by Corynebacterium glutamicum using heterologous aromatic carboxylic acid reductases","authors":"Miku Matsuzawa,&nbsp;Junko Ito,&nbsp;Keiko Danjo,&nbsp;Keita Fukui","doi":"10.1186/s13068-024-02507-3","DOIUrl":"10.1186/s13068-024-02507-3","url":null,"abstract":"<div><h3>Background</h3><p>Vanillin is a flavoring substance derived from vanilla. We are currently developing a biotransformation method for vanillin production using glucose. This report describes the last step in vanillin production: the conversion of vanillic acid to vanillin. First, we selected <i>Corynebacterium glutamicum</i> as the host owing to its high vanillin resistance. The aromatic aldehyde reductase gene (NCgl0324) and vanillic acid demethylase protein subunits A and B gene (<i>vanAB</i>, NCgl2300-NCgl2301) were deleted in <i>C. glutamicum</i> genome to avoid vanillin degradation. Next, we searched for an aromatic carboxylic acid reductase (ACAR), which converts vanillic acid to vanillin. Seventeen ACAR homologs from various organisms were introduced into <i>C. glutamicum.</i></p><h3>Results</h3><p>In vivo conversion experiments showed that eight ACARs were successfully expressed and produced vanillin. In terms of conversion activity and substrate specificity, the ACARs from <i>Gordonia effusa</i>, <i>Coccomyxa subellipsoidea</i>, and <i>Novosphingobium malaysiense</i> are promising candidates for commercial production.</p><h3>Conclusions</h3><p><i>Corynebacterium glutamicum</i> harboring <i>Gordonia effusa</i> ACAR produced 22 g/L vanillin, which is, to the best of our knowledge, the highest accumulation reported in the literature. At the same time, we discovered ACAR from <i>Novosphingobium malaysiense</i> and <i>Coccomyxa subellipsoidea</i> C-169 with high substrate specificity. These findings are useful for reducing the byproducts.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"17 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-024-02507-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140818834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}