Study On Spore Formation Andproteomics Of Spore Germination Atlow PH In Alicyclobacillus Acidoterrestris

Alicyclobacillus acidoterrestrisis a genus of acidophilic,thermophilic,soil-dwelling bacteria,and spores are able to survive under the low pH and high temperature conditions,if conditions werepotentially conducive to cell growth,sporescould germinate rapidly and grow and lead fruit spoilage,which presented an severe challengeto the typical pasteurization in the low pH foodandcontamination control of A.acidoterrestris had become a common concern in the food research field and fruit juice industry.Spore germination was a very important step for the spore revivalandan important stage to control its contaminationdue to losing extreme resistance.In this paper,the effects of nutrient contents and pH value onspore germination of A.acidoterrestris DSM 3922 Twere researched.The involved regulatory mechanisms of spore germination atlow p Hwere investigated byproteomics analysis during spore germination.The results provided a theoretical basis for controlling the hazard of Aacidoterrestris and modifying the pasteurization parameterofthe lowfood.The main research results were as follows:1.Glucose,yeastpowder,Mn²⁺,Mg²⁺hadsignificantimpactonthetotal number of cells and spore production,the growth of cell were inhibited when added excess Mn²⁺or Mg²⁺,and Ca²⁺,NH₄⁺and K⁺had a non-significant impact when worked as a signal factor,but when Ca²⁺worked with K⁺ or NH₄⁺ they could promote spore formation.2.The optimal pH for spore germination of A.acidoterrestris were 4.0 through OD values detection of spore suspension and sopres morphology observation using scanning electron microscopy.Spore germination of A.acidoterrestris was obviously delayedat pH 3.0 and pH 5.0 and spore wallswere destroyed at pH 2.0.3.The result demonstrated that 98 diffetential proteins were identified in spores germination of 2 hat p H3.0.Through gene ontology?GO?analysis,the molecular functionsof differentially expressed proteinswere mainly enriched in the alpha-phosphotriesterase activity,the lactylglutathione lyase activity,the structure constituent of ribosome,the structuremolecule activity,transferase activity,peptidase activity and exopeptidase activity;the related biological processes were mainly enriched in the organicnitrogen compound biosynthesis and metabolism process,protein metabolic process,glutamine metabolic process,the cellular protein metabolic process and organic substrance biosynthetic process.Through Kyoto Encyclopedia of Genes and Genomes?KEGG?analysis,the involved pathways werebeta-lactam resistance,ribosomes,secondary metabolites synthesis,pyruvate metabolism,porphyrin and chlorophyll metabolism,terpenoid backbone biosynthesis,two-component systems and bacterial secretion systems.