Sardar Raj Kumar
CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI), Council of Scientific and Industrial Research (CSIR), Bhavnagar, Gujarat, 364 001, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, U. P - 201 002, India.
World J Microbiol Biotechnol. 2025 Feb 27;41(3):74. doi: 10.1007/s11274-025-04283-0.
High-Density Polyethylene (HDPE) PE is one of the primary contributors of long-lasting and prolonged pollution in the environment. In this study, more than three hundred marine isolates collected off the Gujarat Sea coast were tested for HDPE plastic utilizing ability. Among fifty-one positive noted isolates, RS124 as a potential strain was identified as Micrococcus flavus (accession is PP858228) based on 16 S rRNA gene sequencing and total cellular fatty acid profiling. Initial bacterial adherence on the film surface was shown in a scanning electron microscopy (SEM) image as a key step to biodegradation. Moreover, atomic force microscopy (AFM) shows that the film surface became more fragile, damaged, and rougher than untreated films. Shifts and alterations in peak transmittance with emergence of two new shouldered peak in degraded HDPE observed by fourier transform infrared spectroscopy (FTIR) was associated to chemical and mechanical alteration. Thermogravimetric analysis (TGA) analysis designated larger difference in percent weight loss provisions thermal instability. In the enzymatic study, the highest activity of peroxidase and dehydrogenase was recorded on the 3rd and 4th weeks of treatment with strain, respectively, during co-incubation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis disclosed the presence of a distinct 19 kDa size protein, uncovering its role in the colonization of bacteria on the hydrophilic HDPE surfaces. About 1.8% weight reduction in HDPE was recorded as a result after 30 days of bio-treatment with M. flavus. Hence, the entire observed results reveal that the M. flavus RS124 could be effectively applied for the degradation of HDPE. This is the first report on M. flavus that it exhibits plastic degrading characteristic ever, which may allow for green scavenging of plastic waste.
高密度聚乙烯(HDPE)是环境中长期和持久污染的主要来源之一。在本研究中,对从古吉拉特海岸收集的三百多种海洋分离株进行了HDPE塑料利用能力测试。在51株阳性分离株中,基于16S rRNA基因测序和总细胞脂肪酸谱分析,潜在菌株RS124被鉴定为黄微球菌(登录号为PP858228)。扫描电子显微镜(SEM)图像显示细菌在薄膜表面的初始附着是生物降解的关键步骤。此外,原子力显微镜(AFM)表明,与未处理的薄膜相比,薄膜表面变得更脆弱、受损且更粗糙。傅里叶变换红外光谱(FTIR)观察到降解的HDPE中峰值透光率的变化以及出现两个新的肩峰,这与化学和机械变化有关。热重分析(TGA)分析表明,热不稳定性导致失重百分比存在较大差异。在酶学研究中,在共培养期间,用该菌株处理的第3周和第4周分别记录到过氧化物酶和脱氢酶的最高活性。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)分析揭示了一种独特的19 kDa大小蛋白质的存在,揭示了其在细菌在亲水性HDPE表面定殖中的作用。用黄微球菌进行30天生物处理后,HDPE的重量减少了约1.8%。因此,所有观察结果表明,黄微球菌RS124可有效用于HDPE的降解。这是关于黄微球菌具有塑料降解特性的首次报道,这可能有助于对塑料废物进行绿色清除。