| Plant Jiaosu for Environmental Protection are based on plant as the main raw material,with or without auxiliary materials,and are produced by microbial fermentation and contain specific biologically active ingredients for environmental governance and environmental protection.It contains rich probiotics such as lactic acid bacteria,yeast and acetic acid bacteria,as well as active enzymes,organic acids,polysaccharides,polyphenols and esters.Traditional Plant Jiaosu are prepared by natural fermentation,which takes a long time to prepare(more than 3 months)and is easily contaminated by miscellaneous bacteria,resulting in uneven quality of fermented products.The use of bio-enhanced fermentation to prepare Plant Jiaosu can avoid pollution to a certain extent and improve the quality of products.In addition,the selection and ratio of fermentation raw materials,temperature,inoculum size,sample loading and other factors during the fermentation process will also affect product quality.In recent years,Plant Jiaosu technology has been widely promoted and applied in China.The fermentation of defective fruits into Plant Jiaosu is in line with the concept of "treating waste with waste".good way.In order to explore the feasibility of using bio-enhanced fermentation technology to produce environmentally friendly enzymes in inferior fruits,this study screened strains that can be used for bioenhanced fermentation from natural fermentation Plant Jiaosu,and optimized the fermentation method,fermentation process and fermentation raw material ratio.The fermentation process under the optimal fermentation process was studied,and its deodorization application was evaluated at the same time,in order to provide theoretical basis and guidance for the utilization of residual fruit resources.The main research results are as follows:1.One strain of lactic acid bacteria for fermentation was obtained by comparing the lactic acid production capacity.It was identified as(Lactobacillus paracasei)by Gram staining,16 S r DNA identification and BLAST sequence alignment.After 48 hours of culture,the lactic acid production reached 3.39±0.09 g/L.Preserved in the General Microbiology Center of the China Microorganism Culture Collection Committee(the strain preservation number is CGMCC No.23388);a yeast strain for fermentation was obtained by comparing the aroma-producing ability and biomass.It was identified by 18 S r DNA and BLAST sequence alignment.It was identified as(Candida ethanolica),and the biomass was 2.5 ± 0.17 mg/m L after 72 h of culture.Preserved in the General Microbiology Center of China Microorganism Culture Collection Committee(the strain preservation number is CGMCC No.23387);1 strain of acetic acid bacteria for fermentation was obtained by comparing the acetic acid production capacity,which was identified by Gram staining,16 S r DNA,and BLAST sequence alignment.It was identified as(Acetobacterium tropicalis),and the acetic acid production reached 2.62 ± 0.05 g/L after 48 hours of culture.It is preserved in the General Microbiology Center of China Microorganism Culture Collection Committee(the culture collection number is CGMCC NO.23389).And there is no antagonistic effect between the three strains.2.The lactic acid content was 3.49 ± 0.23 g/L,the acetic acid content was 3.53 ± 0.11 g/L,and the number of effective viable bacteria was 9.50 × 108 CFU/m L in the 30-day fermentation by bio-enhanced fermentation,which were significantly higher than those in the natural fermentin group(P<0.05).The optimal conditions of bio-enhanced fermentation of environmental friendly enzymes obtained by single factor experiment are: sugar source brown sugar,inoculum volume 7%,temperature 35 ℃,sample loading 80%.The optimal ratio of raw materials obtained by the mixed design response surface methodology is sugar: fruit: water = 75: 200: 725.The results of the verification test of the optimal fermentation conditions showed that the total acid content of the fermentation product was 14.49 ± 0.30 g/L,the lactic acid content was 4.18 ± 0.08 g/L,and the acetic acid content was4.08 ± 0.01 g/L after the optimization of the optimal conditions,all of which were significant.Compared with the product before optimization,the number of effective viable bacteria increased by 1 order of magnitude,and the fermentation quality was significantly improved.3.The results of the three-dimensional fluorescence measurement during the fermentation process under the optimal fermentation conditions show that the environmental enzyme in this experiment has a unique characteristic peak,which exists in the range of(λex: 410-440 nm,λem: 500-550 nm);the bacterial microbial community analysis results show that in During the fermentation process,the relative abundance of Acetobacter and Lactobacillus continued to increase,and their relative abundance reached 93.64% at 30 d(Acetobacter 90.35% + Lactobacillus 3.29%),which is the absolute dominant flora in the fermentation system;fungi The results of microbial community analysis showed that Pichia spp.was the absolute dominant flora in all fermentation stages,and the relative abundance of the connected Saccharomyces cerevisiae was 11.58% in the later stage of fermentation.4.The environmental protection enzyme in this experiment has obvious deodorization effect on pig blisters manure.The deodorization effect is the best when the addition amount is 3% and the temperature is 30℃.After 4 days of action,the odor concentration down to 5.01 ± 1.20 mg/m3,compared with 0 days,the odor removal rate was over 99%,and the odor concentration did not increase after that;The high-throughput sequencing results showed that the application of environmental enzymes could reduce the diversity and richness of the microbial community in the system.After the action,the abundance of Pseudomonas increased and became the dominant genus in the system.The abundance of odor-producing bacteria such as Bacillus decreased. |
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