Anjulal H, Singhvi Mamata, Zinjarde Smita
Department of Biotechnology with Jointly Merged Institute of Bioinformatics and Biotechnology, Savitribai Phule Pune University, Pune, 411007 India.
3 Biotech. 2024 Oct;14(10):240. doi: 10.1007/s13205-024-04079-3. Epub 2024 Sep 21.
In the current study, the ability of an indigenous marine Actinomycete (NCIM 5124) to degrade poly(3-hydroxybutyrate)-PHB was examined. From the whole genome sequencing data of the organism, information regarding the PHB depolymerase gene and amino acid sequence (Accession number: MCK9871921.1) was retrieved. In silico studies indicated the presence of a signal peptide characteristic of extracellular enzymes. ProtParam tool predicted that the protein had a molecular mass of 42.46 kDa with an isoelectric point of 4.51. Aliphatic and instability index values suggested that the protein was stable and the observed GARVY value indicated its hydrophilic nature. 3D structure prediction and multiple sequence alignments revealed the presence of Type I catalytic domain [including the oxyanion histidine towards the N terminal, the catalytic triad with serine (as a part of GLSAG pentapeptide), aspartate and histidine], substrate binding and linker domain. The organism was able to grow on PHB in solid and liquid media and effectively degrade it. Maximum enzyme activity (1.8 U/mL/min) was observed after 5 d of incubation in Bushnell Hass Medium containing 0.1% PHB, 1.5% sodium chloride, at 30 °C, pH 7.5 with agitation at 130 rpm. Application of the organism in disintegrating films of PHB and its copolymers was successfully demonstrated on the basis of weight loss and scanning electron microscope analysis. To the best of our knowledge, this is the first report on production of PHB depolymerase with high efficiency by , an organism that holds promise in degrading PHB-derived waste material.
The online version contains supplementary material available at 10.1007/s13205-024-04079-3.
在当前研究中，检测了一种本土海洋放线菌（NCIM 5124）降解聚（3-羟基丁酸酯）-PHB的能力。从该生物体的全基因组测序数据中，检索到了关于PHB解聚酶基因和氨基酸序列（登录号：MCK9871921.1）的信息。计算机模拟研究表明存在细胞外酶特有的信号肽。ProtParam工具预测该蛋白质的分子量为42.46 kDa，等电点为4.51。脂肪族和不稳定性指数值表明该蛋白质是稳定的，观察到的GARVY值表明其具有亲水性。三维结构预测和多序列比对揭示了I型催化结构域的存在[包括靠近N端的氧阴离子组氨酸、具有丝氨酸（作为GLSAG五肽的一部分）、天冬氨酸和组氨酸的催化三联体]、底物结合结构域和连接结构域。该生物体能够在固体和液体培养基中在PHB上生长并有效降解它。在含有0.1% PHB、1.5%氯化钠的布什内尔-哈斯培养基中，于30℃、pH 7.5、130 rpm搅拌条件下培养5天后，观察到最大酶活性（1.8 U/mL/min）。基于重量损失和扫描电子显微镜分析，成功证明了该生物体在分解PHB及其共聚物薄膜方面的应用。据我们所知，这是关于一种有望降解PHB衍生废料的生物体高效生产PHB解聚酶的首次报道。
在线版本包含可在10.1007/s13205-024-04079-3获取的补充材料。
