■甲壳素,丰富的海洋环境,在转型和利用方面提出了重大挑战。一个菌株,T22.7.1T,具有显著的几丁质脱乙酰化能力,是从中国北海的刺五加根际中分离出来的。比较16SrDNA序列分析表明,新分离物与印度尼西亚红球菌CSLK01-03T具有最高的序列相似性(99.79%),其次是R.ruberDSM43338T,R.亲电JC435T,和阿瑟利沃人10bc312T(98.97%,98.81%,98.83%,分别)。随后的基因组测序和系统发育分析证实,菌株T22.7.1T属于印尼菌属。然而,其他分类学特征鉴定出菌株T22.7.1T是一种新型的印尼红菌株,与CSLK01-03T不同。
■本研究完善了印尼红的分类学描述,并研究了其在将几丁质转化为壳聚糖中的应用。对菌株T22.7.1T的几丁质脱乙酰酶(RiCDA)活性进行了优化,并从发酵产物中分离纯化酶。
■通过优化,菌株T22.7.1T的RiCDA活性达到287.02U/mL,是原始酶活性(8.0U/mL)的34.88倍。以31.83的纯化因子对天然CDA酶进行纯化,酶溶液的比活性达到1200.33U/mg。RiCDA表现出良好的pH和温度适应性和稳定性,以及广泛的基材适应性,有效脱乙酰几丁质,壳寡糖,N-乙酰氨基葡萄糖,和其他基材。
■产品分析表明,RiCDA处理将天然甲壳质的脱乙酰度(DD)提高到83%,超过商业壳聚糖。因此,RiCDA显示出作为天然几丁质和壳寡糖的有效脱乙酰工具的巨大潜力,强调其在天然多糖生物精炼中的适用性。
UNASSIGNED: Chitin, abundant in marine environments, presents significant challenges in terms of transformation and utilization. A strain, T22.7.1T, with notable chitin deacetylation capabilities, was isolated from the rhizosphere of Acanthus ebracteatus in the North Sea of China. Comparative 16S rDNA sequence analysis showed that the new isolate had the highest sequence similarity (99.79%) with Rhodococcus indonesiensis CSLK01-03T, followed by R. ruber DSM 43338T, R. electrodiphilus JC435T, and R. aetherivorans 10bc312T (98.97%, 98.81%, and 98.83%, respectively). Subsequent genome sequencing and phylogenetic analysis confirmed that strain T22.7.1T belongs to the R. indonesiensis species. However, additional taxonomic characterization identified strain T22.7.1T as a novel type strain of R. indonesiensis distinct from CSLK01-03T.
UNASSIGNED: This study refines the taxonomic description of R. indonesiensis and investigates its application in converting chitin into chitosan. The chitin deacetylase (RiCDA) activity of strain T22.7.1T was optimized, and the enzyme was isolated and purified from the fermentation products.
UNASSIGNED: Through optimization, the RiCDA activity of strain T22.7.1T reached 287.02 U/mL, which is 34.88 times greater than the original enzyme\'s activity (8.0 U/mL). The natural CDA enzyme was purified with a purification factor of 31.83, and the specific activity of the enzyme solution reached 1200.33 U/mg. RiCDA exhibited good pH and temperature adaptability and stability, along with a wide range of substrate adaptabilities, effectively deacetylating chitin, chitooligosaccharides, N-acetylglucosamine, and other substrates.
UNASSIGNED: Product analysis revealed that RiCDA treatment increased the deacetylation degree (DD) of natural chitin to 83%, surpassing that of commercial chitosan. Therefore, RiCDA demonstrates significant potential as an efficient deacetylation tool for natural chitin and chitooligosaccharides, highlighting its applicability in the biorefining of natural polysaccharides.