In order to degrade soybean dregs in high temperature,thermophilic bacteria were screened from soybean dregs, horse manure, pig manure and domestic sludge. The results showed that 7 thermophilic bacteria strain were gained,which could utilize soybean dregs to grow at 70℃ .Through 16S rDNA identification, they belonged to Geobacillus toebii, Geobacillus sp. , Methylobacterium sp.and Thermus thermophilus,respectively. Among them,Geobacillus toebii (G.T1) was the best for degrading soybean dregs(4.80%).The optimal growth temperature for strain G.T1 was 65℃ ,and optimal initial pH value was 7.5,the strain reached stable growth phase within 24 h.The strain G.T1 was inoculated to soybean dregs (including 5% soybean water sludge) and fermented at 70℃ for 5 d,the carbon-nitrogen ratio (C/N) of the experimental group decreased to 14.43 after 5 d of fermentation,which was lower than the blank(CK).Furthermore,the seed germination index of the experimental group was 135.00%,far higher than that of the CK (86.42%).In addition, as important nutritional indicators of organic fertilizers,the contents of nitrogen,phosphorus and potassium were 27.72,7.69 and 17.92 g/kg in the experimental group,respectively,which were 18.46%,25.04% and 22.74% higher than those in the CK.Therefore,strain G.T1 could not only promote the maturity process of soybean dregs,but also improve the contents of nitrogen,phosphorus and potassium nutrients.
CHEN Xiaojia, LI Li, MA Xinxin, SHI Jiping, ZHAO Zhijun
. Screening and Application of Thermophilic Bacteria for Degrading Soybean Dregs[J]. Journal of Henan Agricultural Sciences, 2021
, 50(1)
: 172
-179
.
DOI: 10.15933/j.cnki.1004-3268.2021.01.022