摘要
利用 2 4株能够降解纤维素和木质素的菌种对玉米秸秆粉进行了单菌株发酵、多菌株组合发酵以及不同氮源发酵生产饲料蛋白的比较研究。结果表明 :2 4株单菌株发酵中 F-2 1的发酵产物真蛋白含量最高 (平均为 7.64 % ) ;以 F-5 ,F-1 7,F-2 1和 F-2 4组成的多菌株发酵体系 ,经 3 d发酵后 ,发酵产物粗蛋白含量由 2 .80 %提高到 1 0 .0 7% ,比原料本身的粗蛋白含量高 2 5 9.6% ;粗纤维含量由 3 8.1 7%降低到 3 6.0 7% ;氨基酸总量由 2 .1 %增加到 5 .7% ,比原料本身高 1 71 .4 % ,且氨基酸种类齐全 ;尿素和 (NH4 ) 2 SO4 的添加量与发酵产物真蛋白含量的关系呈抛物线 ,对相同添加量以尿素效果较好 ,而在尿素中 ,2 %的添加量为最好。聚类分析将 2 4株单菌株发酵后真蛋白含量和对照分为 4组 ,其中 G3{F-1 ,F-2 1 }发酵效果最好。G1{F-3 ,F-5 ,F-6,F-7,F-8,F-1 2 ,F-1 3 ,F-1 5 ,F-1 7,F-1 9,F-2 0 ,F-2 2 }次之 ,G2 {F-2 ,F-4 ,F-9,F-1 0 ,F-1 1 ,F-1 4 ,F-1 8,F-2 3 ,F-2 4 }较差 ,G4 {对照 ,F-1 6}最差。试验结果表明 ,由 F-5 ,F-1 7,F-2 1和 F-2
In order to increase nutritional value and decrease environmental pollution of corn straw,24 fungal strains those could decompose cellulose and lignin were selected to carry out solid state fermentation (SSF) of corn straw.The SSF was conducted by inoculation of either the single strain or different combinations of the multiple strains.All the SSF experiments were designed in a completely randomized way and each treatment was triplicated.The experimental results were treated with variance analysis,Duncan's multiple range test,regression and clustering analysis by SPSS software. For inoculum preparation,the activated 24 strains were respectively cultured in Erlenmeyer flask containing liquid seed medium at 28℃ and 135 rpm for 2 days.In the single strain SSF experiment,each strain was inoculated into SSF medium with a 20% inoculation ratio.In the control culture,none of 24 strains was inoculated.After inoculation,the culture medium were moistened with 3 times of water(w/w) and cultured statically at 30℃ for 3 days.Then the samples were collected from each culture product and dried at 60℃ to constant weight.The protein content in each sample was determined according to GB6432 86.The results showed that the differences in protein contents of fermentation products of 24 strains were statistically significant ( P<0.01 ).Among the 24 strains,F 21 was the more effective strain and gave the highest protein content of 7 64%.Based on the protein contents,the 24 strains and control were divided into 4 different groups,among which their protein contents orders of fermentation products were:G 3 {F 1,F 21}>G 1{F 3,F 5,F 6,F 7,F 8,F 12,F 13,F 15,F 17,F 19,F 20,F 22}>G 2{F 2,F 4,F 9,F 10,F 11,F 14,F 18,F 23,F 24}>G 4{control,F 16}. In the multiple strains SSF experiment,6 different inoculum combinations were adopted.Each combination was consisted of 4 different strains based on the abilities of these strains in single strain SSF experiment,either in increasing protein content of fermentation product,or in decomposing cellulose and lignin,or in cooperating with yeast well.The 6 treatments were Ⅰ:F 6,F 17,F 23,F 24,Ⅱ:F 1,F 17,F 22,F 24;Ⅲ:F 1,F 17,F 23,F 24;Ⅳ:F 6,F 8,F 17,F 24; Ⅴ:F 5,F 17,F 23,F 24;Ⅵ:F 5,F 17,F 21,F 24.Under the same inoculation ratio and other experimental conditions as that in the single strain experiment,the differences in protein contents of the fermentation products of 6 treatments were statistically significant ( P< 0 01).Treatment Ⅵ had the highest protein content of 9 11%.It showed that the multiple strains inoculum was better than the best single strain F 21. In order to further increase protein content of the multiple strains fermentation product,urea and (NH 4) 2SO 4 in different doses of 1 5%,2%,2 5%,3% and 3 5% were respectively added into the basic SSF medium consisting of 90% corn straw and 10% wheat bran.The result showed that urea was better nitrogen resource.Its optimum dose was 2%. According to above results and considering cost and practical application,we selected 2% urea dose as the supplementary nitrogen resource to the basic SSF medium consisting of 90% corn straw and 10% wheat bran.In this medium SSF treatment by using the multiple strains inoculum combination Ⅵ consisting of Penicillium sp., Torula allii,Chaetomium atrosporum and Geotrichum candidum could increase crude protein content by 259 6%,pure protein content by 336 1%,total amino acids content by 171 4%,compared with the non fermented medium,whereas crude cellulose content was decreased from 38 17% before fermentation to 36 07% after fermentation.
出处
《生态学报》
CAS
CSCD
北大核心
2001年第9期1512-1518,共7页
Acta Ecologica Sinica
基金
山西省环境保护局资助项目
