塑料降解菌的筛选及降解效率的研究

我国是塑料产品生产大国,塑料产品的使用产生了大量难以降解的塑料垃圾。为了能获得可高效降解塑料的菌株,本研究以聚乙烯塑料为唯一碳源,筛选出塑料降解菌,通过失重法测定其降解效率,采用16S rDNA序列测定对其进行核酸分类学鉴定。结果:从半降解带土塑料中筛选出9株塑料降解菌,塑料降解菌的降解率为0.33%~4.24%。9株塑料降解菌中,6株为恶臭假单胞菌(Pseudomonas putida),3株为产吲哚金黄杆菌(Chryseobacterium indologenes),恶臭假单胞菌的塑料降解率高于产吲哚金黄杆菌,有进一步开发应用的潜力。China is a major producer of plastic in the world, while the use of plastic products creates a large amount of plastic waste which is difficult to be degraded. In order to obtain strains that can efficiently degrade plastics, polyethylene plastic was used as the sole carbon source to screen plastic degrading bacteria. The degradation efficiency was determined by weight-loss method, and the strains were identified by nucleic acid taxonomy based on 16S rDNA sequencing. Results: 9 plastic degrading bacteria were screened from semi degraded soil plastics, with the degradation rate of 0.33% to 4.24%. Among the 9 strains of plastic degrading bacteria, two-thirds are Pseudomonas putida and one-thirds are Chryseobacterium indologenes. The plastic degradation rate of P. putida is higher than that of C. indologenes. That indicates P. putida has the potential for further development and application.

蜡质降解微生物的筛选、表征及其秸秆降解作用

我国秸秆资源丰富,但其降解速率慢,仍缺乏高效降解菌剂,表面蜡质层破坏是秸秆降解的第一步。本文从林下腐殖土、腐根等材料中筛选蜡质降解菌,分析菌株对叶表蜡质层的破坏作用,并对其秸秆降解作用进行研究。最终筛选出一种降解蜡质效果较好的菌株(L1-1),核酸分类学鉴定该菌株为金黄杆菌(Chryseobacterium)。菌株L1-1的蜡质相对降解率为39%,对叶表面具有较强的破坏作用。单一菌种降解秸秆的能力有限,蜡质降解菌与木质素降解菌或纤维素降解菌组合可提高秸秆降解率,木质素与纤维素降解菌组合相对降解率可达30.4%。本研究结果表明,在秸秆降解中宜采用复合菌群,蜡质降解菌株在其中可能起到先导作用,木质素降解菌与纤维素降解菌共同使用秸秆降解效果较好。