Bacillus cereus s.l., Gram-positive endospore-forming bacilli, persist ubiquitously in different natural habitats and play various ecological roles. Nevertheless, although chitin is one of the most abundant polymer on Earth, the study of the ability of B. cereus s.l. to hydrolyze this polymer were limited to individual B. cereus and B. thuringiensis strains only. Thus, to fill this gap in this research we focused on (i) the linkage between the capability to chitin degradation and the phylogenetic relatedness of B. cereus s.l. strains, and (ii) the genetic background of chitinolytic properties of these bacilli. Our results showed that chitin degradation is common among the B. cereus group members, yet strains clustered into particular phylogenetic groups differ in their chitinolytic capacity. Separate clustering of chitinolytic and non-chitinolytic strains in the phylogenetic tree indicates the ecotypic structure of these isolates. Two proteins belonging to subfamily A (ChiA) and subfamily B (ChiB) of the glycoside hydrolase GH18 family exhibited simultaneous chitobiosidase and endochitinase activities, and are responsible for chitin utilization by environmental B. cereus s.l. isolates.

芽孢杆菌芽孢杆菌（革兰氏阳性形成内生芽孢杆菌）普遍存在于不同的自然栖息地中，并发挥各种生态作用。尽管如此，尽管几丁质是地球上最丰富的聚合物之一，但是蜡状芽孢杆菌sl水解这种聚合物的能力的研究仅限于蜡状芽孢杆菌和苏云金芽孢杆菌菌株。因此，为了填补这项研究中的空白，我们集中在（i）几丁质芽孢杆菌sl菌株的几丁质降解能力与系统发育相关性之间的联系，以及（ii）这些杆菌的几丁质分解特性的遗传背景。我们的结果表明，几丁质芽孢杆菌中甲壳质的降解很普遍。组成员，但聚类到特定的系统发育组的菌株在其几丁质分解能力上是不同的。在系统发育树中，几丁质分解和非几丁质分解菌株的单独聚集表明了这些分离物的生态型结构。属于糖苷水解酶GH18家族的亚家族A（ChiA）和家族B（ChiB）的两种蛋白质同时具有壳聚糖苷酶和内切壳多糖酶活性，并负责环境蜡状芽孢杆菌sl分离株的甲壳质利用。