Research in microbiology最新文献

{"title":"Microbial anti-biofilms: types and mechanism of action","authors":"Ibrahim Mohammed Hussaini ,&nbsp;Oluwafemi Adebayo Oyewole ,&nbsp;Mamunu Abdulkadir Sulaiman ,&nbsp;Abdullahi Idris Dabban ,&nbsp;Asmau Nna Sulaiman ,&nbsp;Reham Tarek","doi":"10.1016/j.resmic.2023.104111","DOIUrl":"10.1016/j.resmic.2023.104111","url":null,"abstract":"<div><p>Biofilms have been recognized as a serious threat to public health as it protects microbes from antimicrobials, immune defence mechanisms, chemical treatments and nutritional stress. Biofilms are also a source of concern in industries and water treatment because their presence compromises the integrity of equipment. To overcome these problems, it is necessary to identify novel anti-biofilm compounds. Products of microorganisms have been identified as promising broad-spectrum anti-biofilm agents. These natural products include biosurfactants, antimicrobial peptides, enzymes and bioactive compounds. Anti-biofilm products of microbial origin are chemically diverse and possess a broad spectrum of activities against biofilms. The objective of this review is to give an overview of the different types of microbial anti-biofilm products and their mechanisms of action.</p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"175 3","pages":"Article 104111"},"PeriodicalIF":2.6,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41238118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biofilms communities in the soil: characteristic and interactions using mathematical model","authors":"Ojeba Innocent Musa ,&nbsp;Sikirulai Abolaji Akande ,&nbsp;Udeme Joshua Josiah Ijah ,&nbsp;Olabisi Peter Abioye ,&nbsp;Asmau Mohammed Maude ,&nbsp;Job Oloruntoba Samuel ,&nbsp;Adamu Mustapha ,&nbsp;Al-Musbahu Abdulrahim ,&nbsp;Alberto Campos García Gusdanis","doi":"10.1016/j.resmic.2023.104149","DOIUrl":"10.1016/j.resmic.2023.104149","url":null,"abstract":"<div><p>There are many different kinds of microorganisms in the soil, and many of them are biofilms because they can make supracellular compounds. Surface-associated microorganisms in a biofilm are encased in a hydrated extracellular polymeric substance that aids in adherence and survival. Numerous different kinds of microorganisms call the soil home. Strong interactions with and among species are made possible by biofilms; this, in turn, might increase the effectiveness with which organic compounds and poisons in soil are degraded. This encouraged us to take a close look at soil biofilm ecosystems, which we do in this paper. In this research, we will look at how soil biofilms arise and how that affects the composition of microbial communities and their function in the soil. Recent years have seen an uptick in interest in questions about biofilm structure and the social interactions of various bacteria. Many concepts elucidating the underlying mathematics of biofilm growth are also presented. Since biofilms are so widespread, this breakthrough in soil biofilm inquiry might help scientists understand soil microbiomes better. Mathematical models further extrapolate the relationships between microbial communities and gives a more precise information as to what is happening in a biofilm. Biofilms can help plants cope with a variety of environmental challenges. Soil quality, plant nourishment, plant protection, bioremediation, and climate change are all influenced by the interplay of biofilm communities. Thus, biofilms play an important role in the development of environmentally friendly and sustainable agriculture.</p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"175 3","pages":"Article 104149"},"PeriodicalIF":2.6,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71485497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bacterial biofilm formation and anti-biofilm strategies","authors":"Sesan Abiodun Aransiola ,&nbsp;Barathi Selvaraj ,&nbsp;Naga Raju Maddela","doi":"10.1016/j.resmic.2023.104172","DOIUrl":"10.1016/j.resmic.2023.104172","url":null,"abstract":"<div><p><span><span>Bacteria are ubiquitous prokaryotes<span><span>. They are involved in biofilm formation and also have the ability to produce anti-biofilm products for biofilm mitigation. This special issue entitled: “Biofilms- community structure, applications and mitigation” of the journal Research in Microbiology was designed to discuss the flexibility of bacterial biofilms and their products under particular circumstances. Given that </span>quorum sensing (QS) controls biofilm growth in some situations, especially for pathogenic bacteria antibiotic evading strategies. In Gram-negative bacteria, N-acyl </span></span>homoserine<span> lactones are the major quorum sensing signaling molecules. Another approach to prevent bacterial biofilm formation may be to inhibit the QS-regulated activities using quorum quenching (QQ). In this context, QS inhibitors and QS enzymes are important because they, respectively, interfere with signal creation, perception, or degradation and chemical modification. There have been numerous reports of QQ enzymes from bacteria. Treatment failure and recurrent staphylococcal infections are also brought on by biofilm development, which boosts an organism's ability to withstand antibiotics and is thought to be a virulence factor in patients. However, polyphenol quercetin antibiofilm activity is naturally available against drug-resistant </span></span><span><em>Staphylococcus aureus</em></span>.</p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"175 3","pages":"Article 104172"},"PeriodicalIF":2.6,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138478443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biofilm formation by selected microbial strains isolated from wastewater and their consortia: mercury resistance and removal potential","authors":"Ivana Radojević ,&nbsp;Violeta Jakovljević ,&nbsp;Sandra Grujić ,&nbsp;Aleksandar Ostojić ,&nbsp;Katarina Ćirković","doi":"10.1016/j.resmic.2023.104092","DOIUrl":"10.1016/j.resmic.2023.104092","url":null,"abstract":"<div><p>Wastewater often contains an increased amount of mercury and, at the same time, resistant microorganisms. During wastewater treatment, a biofilm of indigenous microorganisms is often unavoidable. Therefore, the objective of this research is to isolate and identify microorganisms from wastewater and investigate their ability to form biofilms for possible application in mercury removal processes.</p><p>The resistance of planktonic cells and their biofilms to the effects of mercury was investigated using Minimum Biofilm Eradication Concentration-High Throughput Plates. The formation of biofilms and the degree of resistance to mercury were confirmed in polystyrene microtiter plates with 96 wells. Biofilm on AMB Media carriers (Assisting Moving Bad Media) was quantified using the Bradford protein assay. The removal of mercury ions by biofilms formed on AMB Media carriers of selected isolates and their consortia was determined by a removal test in Erlenmeyer flasks simulating MBBR.</p><p>All isolates in planktonic form showed some degree of resistance to mercury. The most resistant microorganisms (<span><em>Enterobacter </em><em>cloacae</em></span>, <span><span><em>Klebsiella oxytoca</em><em>, </em></span><em>Serratia</em><em> odorifera</em></span>, and <span><em>Saccharomyces cerevisiae</em></span>) were tested for their ability to form biofilms in the presence and absence of mercury, both in polystyrene plates and on ABM carriers. The results showed that among planktonic forms, <em>K. oxytoca</em> was the most resistant. A biofilm of the same microorganisms was more than 10-fold resistant. Most consortia biofilms had MBEC values &gt; 100,000 μg/mL. Among individual biofilms, <em>E. cloacae</em> showed the highest mercury removal efficiency (97.81% for 10 days). Biofilm consortia composed of three species showed the best ability to remove mercury (96.64%–99.03% for 10 days).</p><p>This study points to the importance of consortia of different types of wastewater microorganisms in the form of biofilms and suggests that they can be used to remove mercury in wastewater treatment bioreactors.</p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"175 3","pages":"Article 104092"},"PeriodicalIF":2.6,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10030986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quenching and quorum sensing in bacterial bio-films","authors":"Srinivasan Kameswaran ,&nbsp;Sudhakara Gujjala ,&nbsp;Shaoqing Zhang ,&nbsp;Suresh Kondeti ,&nbsp;Sundararajan Mahalingam ,&nbsp;Manjunatha Bangeppagari ,&nbsp;Ramesh Bellemkonda","doi":"10.1016/j.resmic.2023.104085","DOIUrl":"10.1016/j.resmic.2023.104085","url":null,"abstract":"<div><p><span>Quorum sensing (QS) is the ability of bacteria to monitor their population density and adjust gene expression accordingly. QS-regulated processes include host–microbe interactions, horizontal gene transfer, and multicellular behaviours (such as the </span>growth and development<span> of biofilm). The creation, transfer, and perception of bacterial chemicals known as autoinducers or QS signals are necessary for QS signalling (e.g. N-acylhomoserine lactones). Quorum quenching (QQ), another name for the disruption of QS signalling, comprises a wide range of events and mechanisms that are described and analysed in this study. In order to better comprehend the targets of the QQ phenomena that organisms have naturally developed and are currently being actively researched from practical perspectives, we first surveyed the diversity of QS-signals and QS-associated responses. Next, the mechanisms, molecular players, and targets related to QS interference are discussed, with a focus on natural QQ enzymes and compounds that function as QS inhibitors. To illustrate the processes and biological functions of QS inhibition in microbe–microbe and host–microbe interactions, a few QQ paradigms are described in detail. Finally, certain QQ techniques are offered as potential instruments in a variety of industries, including agriculture, medical, aquaculture, crop production, and anti-biofouling areas.</span></p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"175 3","pages":"Article 104085"},"PeriodicalIF":2.6,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9920681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quercetin's antibiofilm effectiveness against drug resistant Staphylococcus aureus and its validation by in silico modeling","authors":"Anjaneyulu Musini ,&nbsp;Himanshu Narayan Singh ,&nbsp;Jhansi Vulise ,&nbsp;S.S. Sravanthi Pammi ,&nbsp;Archana Giri","doi":"10.1016/j.resmic.2023.104091","DOIUrl":"10.1016/j.resmic.2023.104091","url":null,"abstract":"<div><p><span><em>Staphylococcus aureus</em></span> is typically treated with antibiotics, however, due to its widespread and unselective usage, resistant strains of <em>S. aureus</em><span> have increased to a great extent. Treatment failure and recurring staphylococcal infections are also brought on by biofilm development, which boosts an organism's ability to withstand antibiotics and is thought to be a virulence factor in patients. The present study investigates the antibiofilm activity of naturally available polyphenol Quercetin against drug-resistant </span><em>S. aureus</em><span>. Micro dilution plating and tube adhesion methods were performed to evaluate the antibiofilm activity of quercetin against </span><em>S. aureus</em>. Quercetin treatment resulted in remarkably reduction of biofilm in <em>S. aureus</em><span><span> cells. Further we performed a study to investigate binding efficacies of quercetin with genes icaB and icaC from ica locus involved in biofilm formation. 3D structure of icaB, icaC and quercetin were retrieved from </span>Protein data bank and PubChem chemical compound database, respectively. All computational simulation were carried out using AutoDock Vina and AutoDockTools (ADT) v 1.5.4. </span><em>In silico</em><span> study demonstrated a strong complex formation, large binding constants (K</span>_b) and low free binding energy (ΔG) between quercetin and icaB (K_b = 1.63 × 10⁻⁵, ΔG = −7.2 k cal/mol) and icaC (K_b = 1.98 × 10⁻⁶, ΔG = −8.7 kcal/mol). This <em>in silico</em> analysis indicates that quercetin is capable of targeting icaB and icaC proteins which are essential for biofilm formation in <em>S. aureus</em>. Our study highlighted the antibiofilm activity of quercetin against drug resistant pathogen <em>S.aureus</em>.</p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"175 3","pages":"Article 104091"},"PeriodicalIF":2.6,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10030987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The dynamics of two iron-oxidizing Acidithiobacillus strains in industrial copper sulfide heap-leaching","authors":"Camila Escuti ,&nbsp;Roberto Véliz ,&nbsp;Mauricio Acosta ,&nbsp;Alex Echeverría-Vega ,&nbsp;Gonzalo Araya ,&nbsp;Diego Ayma ,&nbsp;Cecilia Demergasso","doi":"10.1016/j.resmic.2023.104168","DOIUrl":"10.1016/j.resmic.2023.104168","url":null,"abstract":"<div><p>Several species within the <em>Acidithiobacillus</em> (At.) genus can derive energy from oxidizing ferrous iron and sulfur. Two bacterial strains according to their 16S rRNA gene sequences closely related to <em>A</em><em>t</em>. <em>ferridurans</em> and <em>At. ferrivorans</em> were obtained from the industrial sulfide heap leaching process at Minera Escondida (SLH), named D2 and DM, respectively. We applied statistical and data mining analyses to the abundance of <em>At. ferridurans</em> D2 and <em>At. ferrivorans</em> DM taxa in the industrial process over 16 years of operation. In addition, we performed phylogenetic analysis and genome comparison of the type strains, as well as culturing approaches with representative isolates of <em>At. ferridurans</em> D2 and <em>At. ferrivorans</em> DM taxa to understand the differential phenotypic features. Throughout the 16 years, two main operational stages were identified based on the D2 and DM taxa predominance in solution samples. The better suitability of <em>At. ferrivorans</em> DM to grow in a wide range of temperature and in micro-oxic environments, and to oxidize S by reducing Fe(III) revealed through culturing approaches can, in a way, explain the taxa distribution in both operational stages. The isolate <em>At. ferridurans</em> D2 could be considered as a specialist in aerobic sulfur oxidation, while isolate <em>At. ferrivorans</em> DM is a specialist in iron oxidation. In addition, the results from ore samples occasionally obtained from the industrial heap suggest that <em>At. ferridurans</em> D2 abundance was more related to its abundance in the solution samples than <em>At. ferrivorans</em> DM was. This dynamic coincides with previously obtained results in in-lab cell-mineral attaching experiments with both strains. This information increases our knowledge the ecophysiology of <em>Acidithiobacillus</em> and of the importance of diverse physiological traits at industrial bioleaching scales.</p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"175 1","pages":"Article 104168"},"PeriodicalIF":2.6,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0923250823001432/pdfft?md5=7118de03996d368ba954475c56b7103e&pid=1-s2.0-S0923250823001432-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138299847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative genomics sheds light on transcription factor-mediated regulation in the extreme acidophilic Acidithiobacillia representatives","authors":"Pedro Sepúlveda-Rebolledo ,&nbsp;Carolina González-Rosales ,&nbsp;Mark Dopson ,&nbsp;Ernesto Pérez-Rueda ,&nbsp;David S. Holmes ,&nbsp;Jorge H. Valdés","doi":"10.1016/j.resmic.2023.104135","DOIUrl":"10.1016/j.resmic.2023.104135","url":null,"abstract":"<div><p>Extreme acidophiles thrive in acidic environments, confront a multitude of challenges, and demonstrate remarkable adaptability in their metabolism to cope with the ever-changing environmental fluctuations, which encompass variations in temperature, pH levels, and the availability of electron acceptors and donors. The survival and proliferation of members within the <em>Acidithiobacillia</em> class rely on the deployment of transcriptional regulatory systems linked to essential physiological traits. The study of these transcriptional regulatory systems provides valuable insights into critical processes, such as energy metabolism and nutrient assimilation, and how they integrate into major genetic-metabolic circuits. In this study, we examined the transcriptional regulatory repertoires and potential interactions of forty-three <em>Acidithiobacillia</em> complete and draft genomes, encompassing nine species. To investigate the function and diversity of Transcription Factors (TFs) and their DNA Binding Sites (DBSs), we conducted a genome-wide comparative analysis, which allowed us to identify these regulatory elements in representatives of <em>Acidithiobacillia</em>. We classified TFs into gene families and compared their occurrence among all representatives, revealing conservation patterns across the class. The results identified conserved regulators for several pathways, including iron and sulfur oxidation, the main pathways for energy acquisition, providing new evidence for viable regulatory interactions and branch-specific conservation in <em>Acidithiobacillia</em>. The identification of TFs and DBSs not only corroborates existing experimental information for selected species, but also introduces novel candidates for experimental validation. Moreover, these promising candidates have the potential for further extension to new representatives within the class.</p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"175 1","pages":"Article 104135"},"PeriodicalIF":2.6,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0923250823001109/pdfft?md5=38238f74fdda79410ebbbb3969ac016f&pid=1-s2.0-S0923250823001109-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10185051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bioleaching of polymetallic sulphidic mining residues: influence of increasing solid concentration on microbial community dynamics and metal dissolution","authors":"Catherine Joulian,&nbsp;Agathe Hubau,&nbsp;Douglas Pino-Herrera,&nbsp;Anne-Gwénaëlle Guezennec","doi":"10.1016/j.resmic.2023.104112","DOIUrl":"10.1016/j.resmic.2023.104112","url":null,"abstract":"<div><p>Within the European research project NEMO, a bioleaching strategy was developed for efficient metal extraction from bioleach residue currently heap-leached at Sotkamo (Finland) that still contains sulphidic minerals and valuable metals (Ni, Zn, Co, Cu). The strategy of gradually increasing the solid content with 5% steps allowed the adaptation of the consortium up to 20% (w/w) solid content, with efficient metal dissolution and same dominant bacteria. Largest proportions of <em>Sulfobacillus</em> <em>thermosulfidooxidans</em> while Eh increased suggested it to be most involved in iron oxidation. <em>Acidithiobacillus</em> <em>caldus</em> was rather found when pH stabilized, in line with a production of protons from sulphur oxidation that maintained low pH. ‘<em>Acidithiomicrobium</em>’ P2 was favoured towards the end of the runs and at 20% (w/w) solids possibly due to its tolerance to Ni. The use of gene abundance to evaluate biomass in the pulp provided complementary results to classical cell counts in the liquid phase, and suggested a key role of bacteria associated to mineral particles in iron oxidation. Scaling-up in 21-L stirred-tank reactor at 20% (w/w) solids had no detrimental effect on bioleaching and confirmed metal extraction rates. ‘<em>Acidithiomicrobium</em>’ P2 and <em>Sb. thermosulfidooxidans</em> remained main actors. However, the biological activity was considerably reduced at 30% (w/w) solid concentration, which may be due to a too drastic environmental change for the bacteria to adapt to higher solid concentration. Efficient bioleaching of Sotkamo bioleaching residue at high solid concentration was demonstrated, as well as the robustness of the selected moderately thermophilic consortium, at laboratory and pilot scales.</p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"175 1","pages":"Article 104112"},"PeriodicalIF":2.6,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0923250823000876/pdfft?md5=ea1e3033d03269de5e4eb191e6b295dc&pid=1-s2.0-S0923250823000876-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10309766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sulfur oxidation kinetics of Acidithiobacillus caldus and its inhibition on exposure to thiocyanate present in cyanidation tailings wastewater","authors":"Catherine J. Edward,&nbsp;Mariette Smart,&nbsp;Athanasios Kotsiopoulos,&nbsp;Susan T.L. Harrison","doi":"10.1016/j.resmic.2023.104134","DOIUrl":"10.1016/j.resmic.2023.104134","url":null,"abstract":"<div><p>The sulfur oxidation kinetics of an industrial strain of <em>Acidithiobacillus caldus</em> (<em>At. caldus</em>) cultured on elemental sulfur was explored in batch experiments in the absence and presence of thiocyanate (SCN⁻), a toxin inherent within cyanidation tailings wastewater. The Contois rate expression accurately described <em>At. caldus</em> sulfate generation (R² &gt; 0.93) and microbial growth (R² &gt; 0.87). For a culture maintained at 45 °C a maximum specific growth rate (<span><math><mrow><msub><mi>μ</mi><mi>max</mi></msub></mrow></math></span>) of 0.105 h⁻¹, sulfate yield from biomass (<span><math><mrow><msub><mi>Y</mi><mrow><mi>p</mi><mi>x</mi></mrow></msub></mrow></math></span>) of 4.8 × 10⁻⁹ mg SO₄²⁻.cell⁻¹, and Contois affinity coefficient (<span><math><mrow><msub><mi>K</mi><mi>x</mi></msub></mrow></math></span>) of 1.56 × 10⁻⁸ mg S.cell⁻¹ were established. The presence of SCN⁻ (0 mg/L - 20 mg/L) in the bulk solution inhibited the microbial system competitively. Moreover, SCN⁻ impeded microbial growth differentially; the rate expression was therefore partitioned with respect to SCN⁻ concentration and inhibition constants (<span><math><mrow><msub><mi>K</mi><mi>i</mi></msub></mrow></math></span>) were determined for each region. Adaptation to discrete concentrations of SCN⁻ (1 mg/L and 20 mg/L) improved SCN⁻ tolerance in <em>At. caldus</em>; however, adapted strains exhibited reduced sulfur oxidation potential when cultured under thiocyanate-free conditions relative to the non-adapted control strain. To describe the adapted systems accurately, the Contois affinity coefficient (<span><math><mrow><msub><mi>K</mi><mi>x</mi></msub></mrow></math></span>) was revised to reflect the suspected metabolic decline. The derived <span><math><mrow><msub><mi>K</mi><mi>x</mi></msub></mrow></math></span> values increased in magnitude and affirmed an innate reduction in microbial substrate affinity or substrate adsorption capacity. Inclusion of these updated <span><math><mrow><msub><mi>K</mi><mi>x</mi></msub></mrow></math></span> constants within the rate equation suitably represented the experimental data for both adapted <em>At. caldus</em> strains with R² &gt; 0.94. Furthermore, the impact of adaptation on the inhibition kinetics and inhibition mechanism associated with SCN⁻ exposure were reviewed. Thiocyanate inhibited sulfur oxidation non-competitively in the adapted strains, and the shift in inhibition mechanism may be attributed to the compromised metabolic state following adaptation.</p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"175 1","pages":"Article 104134"},"PeriodicalIF":2.6,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0923250823001092/pdfft?md5=ab5d0b7bfee4b9d888a6bd7e62bea358&pid=1-s2.0-S0923250823001092-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41150869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}