Abstract:
Sugarcane bagasse (SB), as a major by-product of sugarcane, is one of the most abundant organic matter and characterized by cheap and easily available carbon source in Hainan Island, China. The objective of this study was to isolate tropical cellulolytic bacteria from Hainan Island and demonstrate their prospects of utilization of SB as a low-cost carbon source to greatly reduce the cost of aquaculture. A total of 97 cellulolytic marine bacteria were isolated, of which, 58 cellulolytic marine bacteria displayed the hydrolysis capacity (HC) of more than 1, while 28 cellulolytic marine bacteria displayed more than 2. Of the 28 tropical cellulolytic bacterial strains with HC more than 2, Microbulbifer sp. CFW-C18 and Vibrio sp. MW-M19 exhibited excellent SB decomposition in a small-scale laboratory simulation of shrimp aquaculture, up to 75.31 and 74.35%, respectively, and both of them were safe for shrimps. Meanwhile, both of CFW-C18 and MW-M19 besides displaying low multiple antibiotic resistance (MAR) index, also increased the C/N ratio (CFW-C18: C/N ratio of 14.34; MW-M19: C/N ratio of 14.75) of the small-scale laboratory simulation of shrimp aquaculture by decreasing the nitrogen content after a supplement of SB for 15 days. More importantly, CFW-C18 and MW-M19 displayed a relatively low MAR index, 0.47 and 0.1, respectively, especially MW-M19, with the lowest MAR index (0.1), which was resistant to only three antibiotics, streptomycin, amikacin, and levofloxacin, indicating that this strain was safe and non-drug resistance for further use. Overall, tropical cellulolytic bacteria isolated from Hainan Island, especially CFW-C18 and MW-M19, will provide the proficient candidates as probiotics for further construction of the recirculating aquaculture system based on the supplement of low-cost external carbon source-SB.
摘要:
甘蔗渣(SB),作为甘蔗的主要副产品,是海南岛最丰富的有机物之一,具有廉价易得的碳源,中国。本研究的目的是从海南岛分离热带纤维素分解菌,并展示其利用SB作为低成本碳源的前景,以大大降低水产养殖成本。共分离出97株纤维素分解海洋细菌,其中,58个纤维素分解海洋细菌的水解能力(HC)超过1,而28个纤维素分解海洋细菌的水解能力超过2。在HC超过2的28个热带纤维素分解细菌菌株中,微球菌属。CFW-C18和弧菌。MW-M19在对虾养殖的小规模实验室模拟中表现出优异的SB分解,高达75.31和74.35%,分别,他们两个对虾都是安全的。同时,CFW-C18和MW-M19除了显示低的多重抗生素耐药性(MAR)指数外,通过补充SB15天后减少氮含量,还增加了小规模实验室模拟对虾水产养殖的C/N比(CFW-C18:C/N比14.34;MW-M19:C/N比14.75)。更重要的是,CFW-C18和MW-M19显示出相对较低的MAR指数,分别为0.47和0.1,尤其是MW-M19,MAR指数最低(0.1),它只对三种抗生素有抗药性,链霉素,阿米卡星,和左氧氟沙星,表明该菌株是安全的和非耐药性的进一步使用。总的来说,从海南岛分离的热带纤维素分解细菌,特别是CFW-C18和MW-M19,将为在补充低成本外部碳源-SB的基础上进一步构建循环水产养殖系统提供熟练的益生菌候选物。