Journal of Phycology最新文献

{"title":"Evidence of sterility of the male sporophytes of the brown alga Saccharina japonica (Phaeophyceae) in culture irrespective of their ploidy levels","authors":"Jing Li,&nbsp;Shaojun Pang","doi":"10.1111/jpy.13530","DOIUrl":"10.1111/jpy.13530","url":null,"abstract":"<p>Monoclonal female gametophytes of <i>Saccharina japonica</i>, when cultured independently, can develop into female sporophytes. Previous research has shown that the chromosomes in female sporophytes of <i>S. japonica</i> may naturally duplicate, forming diploids, and these diploid female sporophytes are capable of forming sori and releasing zoospores. In contrast, male sporophytes derived from culturing monoclonal male gametophytes failed to form sori and produce meiospores; thus, it was hypothesized that these male sporophytes are haploid and unable to perform meiotic division. In order to explore whether the chromosomes in male sporophytes can naturally duplicate and whether such diploid male sporophytes can effectively form sori and produce meiospores, we obtained 62 male sporophytes and cultivated them into adults. Only male-specific DNA markers were detected in all of these male sporophytes, indicating their male nature. Ten microsatellite markers were used to estimate the relatedness of the parental gametophytes and the corresponding sporophytes. Results revealed that the genotypes of the male sporophytes matched exactly with the corresponding male gametophytes. Both diploid and haploid sporophytes were detected in these 62 male sporophytes when analyzed by flow cytometry. After 16 months of cultivation, none of the male sporophytes formed sori regardless of their ploidy. As controls, both female and hybrid sporophytes developed sori and released viable zoospores. These findings suggest that the sterility of male sporophytes in <i>S. japonica</i> is not related to their ploidy; rather, it is attributed to the absence of essential elements for sori formation that may be present only in the female.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"61 1","pages":"241-249"},"PeriodicalIF":2.8,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142770052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effects of temperature and CO2 enrichment on the red seaweed Asparagopsis taxiformis from Southern California with implications for aquaculture","authors":"Hannah M. Resetarits,&nbsp;Gal Dishon,&nbsp;Vinayak Agarwal,&nbsp;Jennifer E. Smith","doi":"10.1111/jpy.13526","DOIUrl":"10.1111/jpy.13526","url":null,"abstract":"<p>The red alga <i>Asparagopsis taxiformis</i> has recently been recognized for its unique ability to significantly reduce methane emissions from ruminant animals when fed in small quantities. The main obstacle in using this seaweed as a methane-mitigating feed supplement is the lack of commercially available biomass. Little is known about how best to grow this red alga on a commercial scale, as there are few published studies that have investigated the factors that influence growth, physiology, and overall performance. This study examined the effects of temperature and CO₂ enrichment on the growth, photophysiology, and concentration of bromoform, the secondary metabolite largely responsible for methane reduction in <i>A. taxiformis</i>. A series of single and multifactor closed culture experiments were conducted on <i>A. taxiformis</i> collected, isolated, and cultured from populations in Southern California. We identified the optimal temperature range to be between 22 and 26°C, with significant short-term stress observed below 15°C and above 26°C. Carbon dioxide addition resulted in increased performance, when accounting for growth per CO₂ use. In general, we observed the highest bromoform concentrations in algae with the highest growth rates, but these results varied among experiments. These findings indicate that through environmental control and by addressing limiting resources, significant increases in biomass production and quality can be achieved.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 6","pages":"1567-1584"},"PeriodicalIF":2.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11670279/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142770054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interactive effects of CO2, temperature, and nitrate limitation on the growth and physiology of strain CCMP 1334 of the marine cyanobacterium Synechococcus (Cyanophyceae)","authors":"Alyssa K. Sharbaugh,&nbsp;Edward A. Laws","doi":"10.1111/jpy.13531","DOIUrl":"10.1111/jpy.13531","url":null,"abstract":"<p>The marine cyanobacterium <i>Synecococcus</i> sp. (CCMP 1334) was grown in a continuous culture system on a 12:12 h light:dark cycle at all combinations of low and high pCO₂ (400 and 1000 ppmv, respectively), nutrient availability (nitrate-limited and nutrient-replete conditions), and temperatures of 21, 24, 28, 32, and 35°C. The maximum nutrient-replete growth rate was ~1.15 day⁻¹ at 32–35°C. Median nutrient-replete growth rates were higher at 1000 ppmv than at 400 ppmv pCO₂ at all temperatures. Carbon:nitrogen ratios were independent of pCO₂ at a fixed relative growth rate (i.e., growth rate ÷ nutrient-replete growth rate) but decreased with increasing temperature. Carbon:chlorophyll <i>a</i> ratios were decreased monotonically with increasing temperature and were higher under nitrate-limited than nutrient-replete conditions. Ratios of phycoerythrin to chlorophyll <i>a</i> were independent of growth conditions. Productivity indices were independent of temperature and nutrient limitation but were consistently higher at 1000 ppmv than 400 ppmv pCO₂. Both growth rates and dark respiration rates were positively correlated with temperature, and the associated <i>Q</i>₁₀ values were 2.2 and 2.3, respectively. A model of phytoplankton growth in which cellular carbon is allocated to structure, storage, or the light or dark reactions of photosynthesis accounted for the general patterns of cell composition and growth rate. This strain of <i>Synechococcus</i> appears well suited to changes in environmental conditions that are expected as the climate warms in response to anthropogenic emissions of CO₂.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"61 1","pages":"77-90"},"PeriodicalIF":2.8,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jpy.13531","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142770053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A sensitive and reliable method for the quantitative determination of hydrogen peroxide produced by microalgae cells","authors":"Monika Hejna,&nbsp;Dominika Kapuścińska,&nbsp;Anna Aksmann","doi":"10.1111/jpy.13524","DOIUrl":"10.1111/jpy.13524","url":null,"abstract":"<p>One of the reactive forms of oxygen is hydrogen peroxide (H₂O₂), which has been investigated as a key component of growth processes and stress responses. Different methods for the determination of H₂O₂ production by animal and bacterial cells exist; however, its detection in algal cell cultures is more complicated due to the presence of photosynthetic pigments in the cells and the complex structure of cell walls. Considering these issues, a reliable, quick, and simple method for H₂O₂ detection is needed in phycological research. The aim of this methodological study was to optimize an Amplex UltraRed method for the fluorometric detection of H₂O₂ produced by microalgae cells, using a wild-type strain of <i>Chlamydomonas reinhardtii</i> as a model. The results showed that (i) potassium phosphate is the most suitable reaction buffer for this method, (ii) a 560 nm wavelength variant is the most appropriate as the excitation wavelength for fluorescence spectra measurement, (iii) a 50:50 ratio for the reaction mixture to sample was the most suitable, (iv) the fluorescence signal was significantly influenced by the density of the microalgae biomass, and (v) sample fortification with H₂O₂ allowed for an increase of the method's reliability and repeatability. The proposed protocol of the Amplex UltraRed method for the fluorometric detection of H₂O₂ produced by microalgae cells can yield a sensitive and accurate determination of the content of the test compound, minimizing measurement errors, eliminating chlorophyll autofluorescence problem, and compensating for the matrix effect. This method can be applied to the study of other microalgae species.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 6","pages":"1356-1370"},"PeriodicalIF":2.8,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142710409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Subarctic sugar kelp (Saccharina latissima, Phaeophyceae) summer productivity and contribution to carbon budgets","authors":"Stéphanie Roy,&nbsp;Christian Nozais,&nbsp;Ladd E. Johnson,&nbsp;Fanny Noisette","doi":"10.1111/jpy.13525","DOIUrl":"10.1111/jpy.13525","url":null,"abstract":"<p>Kelp forests are known to be very productive ecosystems and constitute a central component of the marine carbon cycle in coastal areas. Nevertheless, crucial carbon-related data are missing to be able to include them properly in carbon budgets. A thorough understanding of the kelp contribution to the carbon cycle is especially important in regions prone to experiencing strong seasonal fluctuations in environmental conditions, such as subarctic regions. This study aimed to quantify primary productivity through growth rates and oxygen fluxes of a dominant kelp species in subarctic regions, <i>Saccharina latissima</i>, and to link oxygen fluxes to environmental parameters. Our results showed that strong primary productivity oxygen fluxes coincided with high light levels in July and most of August, while growth rates stayed similar all summer. An overall decline in all primary productivity proxies happened from late August, suggesting a seasonal slowing down of <i>S. latissima</i> metabolism. The estimated quantity of carbon stored in tissue during growth represented from 6% to 28% of the gross primary productivity. Further research is needed to explore how and how much carbon transits through living kelp tissue in different seasons, to better understand the contribution of subarctic kelp to coastal carbon budgets.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 6","pages":"1585-1600"},"PeriodicalIF":2.8,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11670287/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142710426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Occurrence of protease inhibitors in freshwater cyanobacterium Woronichinia naegeliana (Unger) Elenkin","authors":"Beata Bober,&nbsp;Paweł Żmudzki,&nbsp;Ewelina Chrapusta-Srebrny","doi":"10.1111/jpy.13527","DOIUrl":"10.1111/jpy.13527","url":null,"abstract":"<p>Cyanobacteria are known for producing a wide array of secondary metabolites, including non-ribosomally synthesized oligopeptides, whose functions remain to be determined. <i>Woronichinia naegeliana</i>, a common component of freshwater blooms, represents an under-explored resource of bioactive oligopeptides. Among these oligopeptides are cyanopeptolin 1081 and anabaenopeptin 899, which have been shown to have adverse effects on zooplankton. The absolute amino acid configuration of these peptides appears typical relative to other cyanopeptolins and anabaenopeptins. To understand their toxic mechanisms, enzyme assays were conducted. The inhibitory activity of cyanopeptolin 1081 and anabaenopeptin 899 was tested against proteases such as chymotrypsin, trypsin, elastase, thrombin, and carboxypeptidase A, resulting in different activities against these enzymes. Cyanopeptolin 1081 inhibited both chymotrypsin and elastase, while anabaenopeptin 899 inhibited carboxypeptidase A but failed to inhibit the other tested enzymes at a concentration of 37 μM. The inhibitory concentration values determined here highlight that these compounds are among the most potent enzyme inhibitors in freshwater-derived cyanopeptides.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"61 1","pages":"34-43"},"PeriodicalIF":2.8,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142693235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oxygen and pH fluxes in shallow bay habitats: Evaluating the effectiveness of a macroalgal forest restoration","authors":"Cristina Galobart,&nbsp;Cèlia Sitjà,&nbsp;Sònia de Caralt,&nbsp;Jorge Santamaría,&nbsp;Alba Vergés,&nbsp;Jordi Boada,&nbsp;Emma Cebrian","doi":"10.1111/jpy.13520","DOIUrl":"10.1111/jpy.13520","url":null,"abstract":"<p>Marine macroalgae are important primary producers in coastal ecosystems. Within sheltered and shallow bays in the Mediterranean, various Fucalean macroalgae and seagrasses coexist, creating habitats of high ecological importance. These habitats have historically suffered from various disturbances, and on this basis, active restoration actions have been proposed as potential solutions for their recovery. Here, we assessed the restoration success of a 10-year restored macroalgal forest by evaluating the recovery in terms of oxygen and pH fluxes and comparing those data with those of a healthy marine forest and a degraded habitat counterpart. We estimated the overall changes in dissolved oxygen and pH using light and dark community in situ incubations. We also determined the biomass and composition of macroalgal and macroinvertebrate compartments of each assemblage. During light incubations, the healthy and restored forest assemblages showed similar average net oxygen production, 5.7 times higher than in the degraded one, and a greater increase in pH. More than 95% of the incubated biomass corresponded to macroalgal and seagrass species. The restored forest showed a six-fold increase in biomass, most likely being responsible for the recovery of primary production. This work provides empirical evidence that the restoration of a single structural species, once successful in the early stages, can yield positive results by recovering processes such as primary production and dark respiration. Moreover, these results showcase differences in ecosystem functions between healthy (either mature or restored) and degraded habitats, highlighting the importance of protecting and preserving coastal marine forests.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"61 1","pages":"20-33"},"PeriodicalIF":2.8,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jpy.13520","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142667948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genome sequences of toxigenic cyanobacteria from a bloom in Lake Mattamuskeet, North Carolina (United States)","authors":"Jéssica A. Moretto,&nbsp;David E. Berthold,&nbsp;Forrest W. Lefler,&nbsp;Viviana Mazzei,&nbsp;Keith A. Loftin,&nbsp;H. Dail Laughinghouse IV","doi":"10.1111/jpy.13523","DOIUrl":"10.1111/jpy.13523","url":null,"abstract":"<p>Lake Mattamuskeet, the largest lake in North Carolina, USA, has undergone decades-long eutrophication causing reduced water quality and promoting cyanobacterial blooms that may produce toxins. It is therefore necessary to evaluate the cyanobacterial diversity of the lake and their toxigenic potential. We present draft genomes of <i>Microcystis</i>, <i>Pelatocladus</i>, <i>Raphidiopsis</i>, and <i>Umezakia</i> strains isolated from Lake Mattamuskeet. The whole-genome shotgun projects for <i>Umezakia ovalisporum</i> BLCC-F208, <i>Microcystis</i> sp. BLCC-F209, <i>Microcystis</i> sp. BLCC-F210, <i>Pelatocladus</i> sp. BLCC-F211, <i>U. ovalisporum</i> BLCC-F215, and <i>Raphidiopsis</i> BLCC-F218 have been deposited in GenBank under accession numbers JBHFLK000000000, JBHFLL000000000, CP169647, JBHFLM000000000, JBHFLN000000000, and JBHFLO000000000, respectively. Based on the genomic analysis, several biosynthetic gene clusters (BCGs) with varying degrees of similarity to known toxic and bioactive compound gene clusters were identified across the different cyanobacterial strains.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 6","pages":"1349-1355"},"PeriodicalIF":2.8,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142648068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"What constitutes a stigma? A review of isolated pores in raphid diatoms (Bacillariophyceae) and the value of precise terminology","authors":"Eileen J. Cox,&nbsp;Bart Van de Vijver","doi":"10.1111/jpy.13522","DOIUrl":"10.1111/jpy.13522","url":null,"abstract":"<p>Scanning electron microscopy has revealed variation in the ultrastructure of distinctive isolated pores in or near the central area of raphid diatoms, with different types of pores being restricted to phylogenetic groups. Thus, the widespread use of the term stigma for all such pores not only hides the structural diversity but also obscures the phylogenetic distribution of the different types. This paper provides images of the different types of isolated pores, particularly refining the discrimination of variants within the Cymbellales, and reveals some interesting ecological patterns. Revised definitions of stigmata and stigmoids are proposed, together with the recognition and definition of another type of stigmoid. The restricted distribution of more precisely defined pore types shows the importance of consistent use of terminology and its relevance to phylogenetic studies.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 6","pages":"1498-1513"},"PeriodicalIF":2.8,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11670289/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142648071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Allelopathic activity of cyanobacteria isolated from Lake Tuzkol","authors":"Nurziya R. Akmukhanova,&nbsp;Sandugash N. Seiilbek,&nbsp;Sandugash K. Sandybayeva,&nbsp;Bolatkhan K. Zayadan,&nbsp;Meriç Albay,&nbsp;Dariga K. Kirbayeva","doi":"10.1111/jpy.13521","DOIUrl":"10.1111/jpy.13521","url":null,"abstract":"<p>Allelopathy plays a crucial role in shaping phytoplankton community dynamics and diversity. It influences competition between photoautotrophs for resources and affects species succession in aquatic ecosystems. This article evaluates the allelopathic activity of cyanobacteria isolated from Lake Tuzkol, Kazakhstan. The allelopathic effects, including growth inhibition or stimulation, were assessed by adding cell-free filtrates of the cyanobacteria <i>Oscillatoria</i> sp. SS-9, <i>Nostoc</i> sp. CZS 2205, <i>Synechococcus</i> sp. SS-5, or <i>Anabaena</i> sp. SS-8 to the tested microalgae. The most pronounced effect was observed with <i>Nostoc</i> sp. CZS 2205, which reduced the cell counts of <i>Chlorella vulgaris</i> SP BB-2 and <i>Chlamydomonas reinhardtii</i> CC-124 by 60% and 57%, respectively, and <i>Scenedesmus quadricauda</i> CC-1 and <i>Ankistrodesmus falcatus</i> CB-2 by 55% and 53%, respectively. <i>Synechococcus</i> sp. SS-5, in contrast, stimulated the growth of <i>Chlorella vulgaris</i> SP BB-2 and <i>Scenedesmus quadricauda</i> CC-1 by 11% and 8.8%, respectively. Filtrates from <i>Oscillatoria</i> sp. SS-9 and <i>Anabaena</i> sp. SS-8 had no significant impact on microalgal growth. Considering the significant allelopathic activity of <i>Nostoc</i> sp. CZS 2205, an agar diffusion test using biomass extracts confirmed a significant inhibitory effect, with the biomass extracts showing stronger activity than cell-free filtrates. A detailed analysis of the cell-free filtrates revealed eight compounds, including methyl heptadecanoate, methyl eicosanoate, tricosane, methyl octadeca-9,12-dienoate, methyl 13,16-octadecadienoate, and 2,2-dimethoxybutane. Additionally, nostocyclamide, a cyclic peptide, was identified in the biomass extract. The detection of nostocyclamide emphasizes its ecological importance and potential evolutionary role. These results enhance our understanding of the role of cyanobacteria in aquatic ecosystems and lay the groundwork for future research into their ecological applications.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 6","pages":"1557-1566"},"PeriodicalIF":2.8,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142622670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}