Biodegradation of natural rubber and deproteinized natural rubber by enrichment bacterial consortia
Biodegradation of natural rubber and deproteinized natural rubber by enrichment bacterial consortia
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DOI：
10.1007/s10532-020-09911-0
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发表时间：
2020-09-10
期刊：
影响因子：
3.6
通讯作者：
Fukuda, Masao
中科院分区：
文献类型：
--
作者：
Nguyen, Lan Huong;Nguyen, Hoang Dung;Fukuda, Masao
研究了从越南橡胶加工厂废弃物中提取的菌群对天然橡胶(NR)和脱蛋白天然橡胶(DPNR)的生物降解作用。结果表明，在NR和DPNR中均有降解，且DPNR比NR更容易降解。培养14天后，添加DPNR的第4组增重率最高，为48.37%，第5组增重率为35.39%。凯氏定氮法和傅里叶变换红外光谱(FTIR)分别测定的氮含量和脂肪酸含量在孵育后显著降低。用核磁共振波谱分析降解胶膜的结构，发现胶膜中含有乙醛基团，这是胶膜降解的标志。扫描电子显微镜观察到细菌细胞紧密附着并嵌入到NR和DPNR膜中。通过16S rRNA基因序列的元基因组分析，确定了与NR和DPNR在细菌组成上的差异。类杆菌和变形杆菌可能在蛋白质或脂肪等非异戊二烯化合物的降解中发挥作用，而放线菌在所有联合体中对橡胶烃的降解起着关键作用。
This study examined the biodegradation of natural rubber (NR) and deproteinized natural rubber (DPNR) by bacterial consortia enriched from a rubber-processing factory's waste in Vietnam. The results reveal the degradation in both NR and DPNR, and the DPNR was degraded easier than NR. The highest weight loss of 48.37% was obtained in the fourth enrichment consortium with DPNR, while 35.39% was obtained in the fifth enrichment consortium with NR after 14 days of incubation. Nitrogen content and fatty acid content determined by Kjeldahl method and fourier transform infrared spectroscopy (FTIR), respectively, were decreased significantly after being incubated with the consortia. Structure of degraded rubber film analyzed by nuclear magnetic resonance spectroscopy showed the presence of aldehyde group, a sign of rubber degradation. Bacterial cells tightly adhering and embedding into NR and DPNR films were observed by scanning electron microscopy. There were differences in the bacterial composition of the consortia with NR and DPNR, which were determined by metagenomic analysis using 16S rRNA gene sequencing. The phylaBacteroidetes andProteobacteriamay play a role in the degradation of non-isoprene compounds such as protein or lipid, while the phylumActinobacteriaplays a crucial role in the degradation of rubber hydrocarbon in all consortia.