Mechanism Study On Inhibiting Corruption Of Kitchen Waste By Lactobacillus Plantarum

Kitchen waste is a kind of potential resource. Before its resource processing, it is usuallytakes more than1or2d on collection and preservation. During this period, the kitchen waste willbecome rotten, leading to the accumulation of bacteria and toxins. If the kitchen waste is wellpreserved, it can be used as the raw material of resources. Otherwise it can only be treated asgeneral garbage, and waste a lot of money to deal with it. Traditional food presercationtechniques, such as pasteurization, cryopreservation, etc., that needs large equipment and moreinvestment, are not suitable for in-situ anti-bacteria in the family. In this dissertation, we used theLactobacillus plantarum to suppress the kitchen waste from spoilage, an by measuring thecontent of the organic acid and biogenic amines, to indicate the effect of it. We also used thedenaturing gradient gel electrophoresis (DGGE) to study the microbial community changes inthe preservation process, that will help us to understand the mechanism how the Lactobacillusplantarum to achieve prevent kitchen waste from spoilage.The main conclusions of this dissertation are as follows:(1) Methods for the determination of organic acids and biogenic amines in kitchen wastewere established. When the use of ion chromatography for the determination of organic acids,and organic acids, all the organic acid’s detection limit were less than0.46mg/L,and the relativestandard deviations（n=3）were lower than2%. Using the dansyl chloride as pre-columnderivatization agent,5biogenic amines derivatives are separated by highe performance liquidchromatography (HPLC). The influence of derivatising condition (the pH of buffer, the samplepreparation steps, the extraction solution) on the derivatising reaction is investigated. Under theoptimal conditions, all the detection limit of five kinds of biogenic amines were lower than0.25mg/L, and the relative standard deviations（n=3）were better than5.4%.(2) The physical and chemical changes in kitchen waste during the preservation werestudied. In terms of the impact of corruption on kitchen waste，37℃was much better for therapid reproduction of lactic acid, although both37℃and45℃helped to rapidly reduce pH. Inaddition，productions of putrescine in37℃were far below the ones in20℃and30℃，indicating that it was significant to reduce odor biogenic amine by appropriately raisingtemperature. In terms of the interactive impact of biomass components and temperatures on thecorruption of kitchen waste，the temperatures and the starch content were not the influencingfactors about various biogenic amines content，but the content of protein and vegetable in kitchenwaste. (3) A preliminary study was lauched about the inoculum of lactic acid bacteria impactingon organic acids and biogenic amines in kitchen waste.The study showed that it was not obviousfor the inhibition of biogenic amine in kitchen waste to make2%of inoculum. Initial pH valueof the kitchen waste could be quickly reduced by making10%of Lactobacillus plantarum. Andthe productions of the lactate were nearly twice more than ones of spontaneous corruption lactate.Inoculating10%of the lactic acid bacteria could significantly inhibit the development ofbiogenic amines, and productions of putrescine were less than a half of ones of spontaneouscorruption putrescine. Productions of histamine reduced by nearly30%than productions ofspontaneous ones，indicating that inoculating10%of the lactic acid bacteria could bring out agood antiseptic effect on the corruption of restaurant garbage.By using PCR-DGGE technology, changes of microbial community in the kitchen waste ofdifferent biomass components and in the inoculating sample of different lactic acid bacteria hadbeen researched during the storage time. Through the PCR-DGGE cluster analysis, the resultsshowed that the changes of nutrients in kitchen waste within a certain range would not take aserious effect upon the succession of microbial community and cluster differences mainlyfocused on the preservation time. In the first6hours, microbial communities had changed a lotin the kitchen waste, where the inoculation of lactic acid bacteria were used to inhibit corruption.After samples of spontaneous corruption were sequenced, some bacteria were detected asfollows, four strains of Lactobacillus plantarum, four strains of Lactobacillus fermentum, onestrains of Weissella cibaria, one strain of Bacterium DT17and one strain of Lactobacillusdelbrueckii subsp., two strains of uncultured bacteria. After inoculation of lactic acid bacteria,dominant bacteria mainly included one strain of Weissella cibaria, three strains of Lactobacillusfermentum. Compared with the natural corruption sample, dominant bacteria had less species,suggesting that the lactic acid bacteria had a inhibited effect on the growth of most microbes.