Isolation and Degradation Effect of Facultative Anaerobic Flora with High Efficiency Organic Matter Biodegradation from Near-Shore Wetland in Taihu Lake

A facultative anaerobic flora with high efficiency in organic matter biodegradation was isolated from the near-shore wetland in Taihu Lake using a new gradient intermittent oxygen exposure technology.The dominant bacteria were isolated and identified.The microbial population structure was measured during the biodegradation period,and the organic matter removal rates were calculated.The results showed that there were nearly no obligatory anaerobic bacteria or obligatory aerobic bacteria in the screened facultative anaerobic bacteria,and the TOM degradation rate during the screening process was about 21% in the later period of the screening experiment.The dominant bacteria,named FA4,FA10 and FA14,were isolated and identified.16S rDNA results showed that they belonged to Pseudomonas sp.,Flavobacteriaceae bacterium and Haematobacter sp.respectively.The facultative anaerobic bacteria population sizes and bacteria activity ETS value in the treatment group,which inoculated the dominant bacteria and the screened facultative anaerobic flora,were higher than those in the control group.The facultative anaerobic bacteria population size(lg(MPN/g),dry weight;maximum probability may quantity(MPN)) and ETS value in the control group were about 4.9 and 85(μg INTF/(g·2 h),dry weight),respectively.On the other hand,the facultative anaerobic bacteria population size and ETS value in the treatment groups were all above 5.4 and 240(μg INTF/(g·2 h),dry weight),respectively.The screened facultative anaerobic bacteria and flora could adapt to the environment well,and degrade organic matter effectively.In seven days,the BOD5 of near-shore wetland sediment in the treatment groups with bacterial inoculation were all reduced by above 90%,while the BOD5 of near-shore wetland sediment in the control group was reduced by 56% only.The TOM degradation rate in the treatment group was about 2.0-2.6 times that of the control group.In three days,the TOM degradation rate of the control group was around 5%,but the TOM degradation rates in the treatment groups,inoculated by FA4,FA10,and FA14 and bacterial consortia(FAG) respectively,were around 10%,13%,10% and 12%,respectively.