Data_Sheet_2_Chryseobacterium lacus sp. nov. Isolated From the Surface Water of Two Lakes With Light-Induced Carotenoid Production.docx

Two Gram-stain-negative, rod-shaped, gliding, catalase-positive, and facultative anaerobic strains, YLOS41T and XH07, were isolated from surface water of Yilong Lake and West Lake of Dali in Yunnan Province, respectively. Both strains were yellow-colored under light conditions and white-colored under dark conditions. The results of physiological and chemotaxonomic characterization, sequencing and phylogenetic analysis, and draft genome sequence comparison demonstrated that the two strains represented a single novel species within the genus Chryseobacterium, for which the name Chryseobacterium lacus sp. nov. is proposed. The type strain is YLOS41T (= KCTC 62352T = MCCC 1H00300T), and the second strain is XH07 (= KCTC 62993). During the cultivation process, we found that the colony color of the two strains changed from white to yellow with illumination. The study investigated the effects of light irradiation on the strain YLOS41T. Results showed that light irradiation did not affect the growth of cells but significantly increased carotenoid synthesis, which caused the change of colony color. In-depth metabolic analysis was conducted by transcriptome. The predominant changes were found for genes involved in carotenoid synthesis as protection from light damage. Based on the genome and transcriptome, we proved that strain YLOS41T possessed a complete synthetic pathway of carotenoid and speculated that the production was zeaxanthin. This was the first report of Chryseobacterium species with light-induced carotenoid synthesis. This study enhances our present knowledge on how Chryseobacterium species isolated from surface water responds to light damage.

两株革兰氏染色阴性（Gram-stain-negative）、杆形、可滑动运动、过氧化氢酶阳性且兼性厌氧的菌株YLOS41^T与XH07，分别分离自云南省异龙湖与大理西湖的表层水体。两株菌株在光照条件下呈黄色，黑暗条件下则为白色。通过生理特性与化学分类学表征、测序及系统发育分析、草图基因组序列比对，结果证实两株菌株隶属于金黄杆菌属（Chryseobacterium）中的一个独立新物种，故提议将其命名为Chryseobacterium lacus sp. nov.。模式菌株为YLOS41^T（= KCTC 62352^T = MCCC 1H00300^T），另一株菌株为XH07（= KCTC 62993）。培养过程中我们发现，两株菌株的菌落颜色会随光照从白色逐渐转变为黄色。本研究探究了光照对菌株YLOS41^T的影响，结果显示光照并未影响菌体生长，但显著提升了类胡萝卜素（carotenoid）的合成量，进而引发菌落颜色变化。通过转录组（transcriptome）测序开展了深度代谢分析，发现与类胡萝卜素合成相关的基因表达变化最为显著，这类基因的功能为抵御光损伤。基于基因组与转录组数据，本研究证实菌株YLOS41^T拥有完整的类胡萝卜素合成通路，并推测其合成产物为玉米黄质（zeaxanthin）。这是首次报道具有光诱导类胡萝卜素合成特性的金黄杆菌属物种。本研究加深了学界对于从表层水体分离的金黄杆菌属物种如何应对光损伤的认知。