Laboratory of Basic and Applied Molecular Biotechnology, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University Gokasho, Uji, Kyoto, Japan.
Laboratory for Environmental Biotechnology, Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Nonoichi, Ishikawa, Japan.
Biosci Biotechnol Biochem. 2024 Nov 22;88(12):1487-1495. doi: 10.1093/bbb/zbae126.
Brown algae are one of the most abundant biomasses on Earth. To recycle them as blue carbon sources, an effective decomposition system is necessary. This study focused on microorganisms present in seawater that decompose brown algae which contain laminarin and alginate. Where Undaria and Sargassum spp. were present, genera Psychromonas, Psychrobacter, and Pseudoalteromonas were predominant in seawater, while genera Arcobacter and Fusobacterium increased in abundance during the process of decomposition. The inoculation of Undaria samples into laminarin-minimal media led to a predominance of Pseudoalteromonas species. A Pseudoalteromonas isolate, identified as Pseudoalteromonas distincta, possesses genes encoding a putative laminarinase, polysaccharide lyase family 6 (PL6) alginate lyases, and a PL7 alginate lyase. The culture media of P. distincta contained no monosaccharides, suggesting the rapid conversion of polysaccharides to metabolites. These findings indicated that Pseudoalteromonas species play a major role in the decomposition of brown algae and affect the microbiota associated with them.
褐藻是地球上最丰富的生物量之一。为了将它们回收为蓝碳资源，需要一个有效的分解系统。本研究集中于存在于海水中的微生物，这些微生物分解含有褐藻淀粉和褐藻胶的褐藻。在裙带菜和马尾藻属存在的情况下，海水中主要存在嗜冷菌属、假单胞菌属和假交替单胞菌属，而弧菌属和梭菌属在分解过程中丰度增加。将裙带菜样本接种到褐藻淀粉最小培养基中，导致假交替单胞菌属占优势。一种假交替单胞菌分离株，鉴定为distincta 假交替单胞菌，具有编码一种假定的褐藻淀粉酶、多糖裂解酶家族 6 (PL6) 褐藻胶裂解酶和一种 PL7 褐藻胶裂解酶的基因。P. distincta 的培养基中没有单糖，表明多糖被迅速转化为代谢物。这些发现表明，假交替单胞菌属在褐藻的分解中起主要作用，并影响与之相关的微生物群落。
