为提高堆肥中添加难溶性磷的转化效率,对筛选于高温堆肥中的耐高温解无机磷菌株(BL161)解磷条件进行优化研究.利用正交设计表L25(5^6)选择培养时间,温度,pH,磷矿粉添加量和菌剂接种比例作为参考因素,对该菌株进行发酵培养.结果表明:该菌株的最佳解无机磷条件是培养基pH为4.5,磷矿粉添加量与接种量分别为9.0 g/L和7%,于38℃下培养25 d,解磷总量(274 mg/L)达到最大;对温度指标分析显示,该菌株的温度耐受范围较广,在3450℃下均能进行解无机磷活动,38℃为最适解无机磷培养温度;该菌株的耐热性较高,在50℃下能够很好地定植和解无机磷,发酵液中ρ(磷矿粉)随着培养时间的增加呈上升趋势,并于培养的第25天达到209 mg/L;极差分析显示,发酵时间对解磷总量的影响最大(R时间=152.2),其他各因素对解磷总量的影响大小依次为pH〉温度〉磷矿粉添加量〉接种量.
In order to increase the conversion efficiency of insoluble phosphorus in compost,a phosphorous dissolving condition was optimized for heat-resistant inorganic phosphorus strains(BL161) screened from high-temperature compost.Orthogonal design table L25(56) was used to select time,temperature, pH,additive phosphorus quantity and proportion of inoculum as reference factors in BL161 fermentation.The results of the orthogonal design software analysis indicated that optimal inorganic phosphorus degradation culture medium for this microorganism was pH 4.5,quantity of ground phosphorus 9.0(g/L) and inoculum 7%.The soluble phosphorus content achieved the highest value(274(mg/L)) at temperature(38 ℃) after 25 days.Temperature target analysis demonstrated that this microorganism had a broader temperature tolerance;it could carry out the degradation of inorganic phosphorus at temperatures 34-(50 ℃),while(38 ℃) was the most suitable temperature for culturing inorganic phosphorous.This microorganism had a better growth and degradation of phosphorus at temperature(50 ℃) due to its high heat-resistance.The quantity of soluble phosphorus in the fermentation broth had an ascending trend with increasing culture time,achieving 209(mg/L) at the 25th day. Analysis of extreme differences indicated that fermentation time had the maximum influence on the total quantity of soluble phosphorus in the fermentation fluid(Rtime=152.2).Other factors affecting the total amount of phosphorous degeneration followed as pH〉Temperature〉ground quantity of additive ground phosporus〉quantity of inoculum.