Studying The Utilization Of Yeast And Bacteria In Amino Acid Mother Liquor

The waste disposal of amino acid industry has been the hot spot of environmental protection field.With the hair hydrolysis of waste liquid from the extraction of amino acids as nitrogen source,feeding yeast and bacteria was used to produce high quality protein feedstuff from amino acid containing wasted liquid is one of the important methods of processing waste liquid.In the case of S.cerevisiae which was used to produce high quality protein feedstuff from amino acid containing wasted liquid by solid or liquid-state fermentation.The results showed that the optimum medium of S.cerevisiae including amino acid waste liquid 15%,molasses 6%,KH₂PO₄ 0.2%,MgSO₄ 0.1 %,with Sodium hydroxide to adjust pH 5.5.After cultured at 30℃ for 24,the total number of yeast reached 3.85×108cfu / m L,the ammonia transformation efficiency was 28.21%.Mixed the 24-hours-culture with soybean meal with a ratio of 0.7/1,the fermentation parameters were cultivation at 35℃for 48 h,the crude protein and TAA content in the fermented soybean meal reached 45.81% and 38.77%,respectively,the volatile base nitrogen conversion efficiency was 59.24%.Compared with the original soybean meal,the contents of crude protein and total amino acid increase by 12.89%and 9.15%.There were four strain including C.utilis,S.cerevisiae,tropical candida,bacillus subtilis were investigated in fermentation experiments,the results showed that the tolerance of amino acid waste liquid of yeast was at higher level.In liquid content was 20%,the total number of S.cerevisiae reached 1.51 x 108 cfu/mL,the total number of C.utilis 1087 reached 1.17 x 108 cfu/m L when the liquid content was 25%.When waste water content was 10%,bacillus subtilis had the largest number of living bacterium,up to 10 x 108 cfu/m L,but when the content of waste liquor was 20%,the number of living bacterium was only 0.298 x 108 cfu/m L,which signified that there was a large different among the tolerance of amino acid waste liquid of different yeasts.In the liquid content was 20%,the total number of C.utilis 1767 reached 4.75 x 108 cfu/mL,the C.utilis 1087 was 1.12 x 108 cfu/mL,all of which signified that there was a large different among the tolerance of amino acid waste liquid of yeasts belong to the same genus and specie but different strains.The optimum medium was study based on economic and simple reasons,the medium including amino acid waste liquid 8%,molasses 8%,KH₂PO₄ 0.5%,After cultured at 30℃ for 24,the total number of C.utili 1087 reached 2.75 x 108 cfu / mL,the ammonia transformation rate was 23.98%.