Ali Maaly H, Aljadaani Saja, Khan Jehan, Sindi Ikhlas, Aboras Majdah, Aly Magda M
Pak J Biol Sci. 2020 Jan;23(2):139-149. doi: 10.3923/pjbs.2020.139.149.
Chitinase enzymes have a various application in the field of environmental, biotechnology and medical aspects. This study aimed to the production of the chitinolytic enzymes from different species of bacteria.
Bacterial isolation from different habitats was carried out on agar medium containing chitin as carbon and nitrogen sources. The obtained bacteria (20) were characterized and screened again in chitin broth medium.
Out of 20 bacterial isolate, 2 new isolates, belonged to Streptomyces laurentii SN5 and Cellulosimicrobium funkei SN20, were the most active in chitin degradation compared to the other isolates. They have been characterized for the first time for their chitinase activity. They were identified using 16S rRNA gene analysis and in the liquid medium, the 2 isolates have enzyme activities of 0.533 and 0.537 U mL-1, respectively. The maximum chitinase production was obtained when those bacterial strains were grown in Luria-Bertani (LB) broth amended with 1% colloidal chitin, for 1 day and at temperature of 30°C. The optimum pH value for chitinase production was pH 7 for both S. laurentii and C. funkei. The enzyme has been purified using Sephadex G-100 and DEAE-Cellulose chromatography column and found to have a similar molecular size of ~50 kDa.
Those two bacterial species could be used in chitinase production and in the environmental recycling of disposable chitin wastes such as chitin from shrimp shell waste.
几丁质酶在环境、生物技术和医学领域有多种应用。本研究旨在从不同种细菌中生产几丁质分解酶。
在以几丁质作为碳源和氮源的琼脂培养基上，从不同生境中分离细菌。对获得的20株细菌进行了表征，并在几丁质肉汤培养基中再次进行筛选。
在20株细菌分离物中，2株新分离物，即劳伦链霉菌SN5和丰克纤维微菌SN20，与其他分离物相比，在几丁质降解方面活性最高。它们首次因其几丁质酶活性而得到表征。通过16S rRNA基因分析对它们进行了鉴定，在液体培养基中，这2株分离物的酶活性分别为0.533和0.537 U mL-1。当这些细菌菌株在添加1%胶体几丁质的Luria-Bertani（LB）肉汤中于30°C培养1天时，几丁质酶产量最高。劳伦链霉菌和丰克纤维微菌产生几丁质酶的最适pH值均为pH 7。该酶已通过Sephadex G-100和DEAE-纤维素色谱柱进行纯化，发现其分子大小相似，约为50 kDa。
这两种细菌可用于生产几丁质酶以及对一次性几丁质废物（如虾壳废物中的几丁质）进行环境回收利用。
