What are the characteristics of psychrotrophic bacteria?
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Psychrotrophic bacteria are organisms that are capable of growing at temperatures below 7°C, with their optimum growth temperature typically between 20 and 30°C . They are found in various environments such as freezers, soil, sewage, and dairy products . Psychrotrophic bacteria include both Gram-negative and Gram-positive species, with Pseudomonas spp., particularly Ps. fluorescens, being dominant in raw and pasteurized milk . These bacteria produce extracellular, heat-resistant enzymes that remain active even after pasteurization and ultrahigh-temperature treatment . They are also known for their ability to spoil milk and other short shelf-life dairy products . Phenotypic characterization of psychrotrophic bacteria can involve determining their proteolytic and lipolytic activities, as well as the production of lecithinases and hemolytic factors .
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120 Citations | Psychrotrophic bacteria are able to grow below 7°C and include both Gram-negative and Gram-positive bacteria from various genera. |
| Psychrotrophic bacteria, such as Arthrobacter spp., are Gram-positive microorganisms that can grow at low temperatures and contaminate various food products, causing spoilage or contributing to the production of taste, flavor, and color in smear cheeses. | |
| Psychrotrophic bacteria can grow at or below 7°C and can spoil milk and other short shelf-life dairy products. | |
| Psychrotrophic bacteria are capable of growth at temperatures below 7°C, with an optimum growth temperature between 20 and 30°C. | |
| The characteristics of psychrotrophic bacteria include the ability to grow at low temperatures, adaptation to freezing conditions, and susceptibility to antibiotics. |
Related Questions
What is the effect of Hexyl Isovalerate on the growth of psychrotrophic bacteria?3 answersHexyl isovalerate has been evaluated for its effect on the growth of psychrotrophic bacteria. It was found that increasing the solids content of skim milk with non-fat milk powder, which includes hexyl isovalerate, produces a growth medium more suitable for growth and protease production for selected psychrotrophic bacteria. Additionally, psychrotrophic bacteria have been found to occur in constantly warm environments, and their growth rates can be influenced by temperature. Some isolates of psychrotrophic bacteria have evolved enhanced growth potential near the optimum temperature in response to a constantly warm environment. However, there is no specific information available on the direct effect of hexyl isovalerate on the growth of psychrotrophic bacteria in the abstracts provided.
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How do psychrophilic bacteria survive in cold temperatures?5 answersPsychrophilic bacteria survive in cold temperatures through various adaptive mechanisms. These include changes in membrane composition, induction of specific cold-active proteins, production of cold stress proteins, and modification of gene expression. These bacteria have the ability to sense changes in environmental temperature and regulate the expression of genes required for survival. They also increase membrane fluidity, decrease activation energy for enzyme activity, produce cold shock chaperones, induce cold-inducible genes, inhibit cold denaturation of proteins, and enhance transcription and translation efficiency. These adaptations allow psychrophilic bacteria to thrive and maintain metabolic activity at low temperatures.
What are the psychrophilic microorganisms in meat?4 answersPsychrophilic microorganisms in meat include bacteria, yeast, and fungi. These microorganisms can be found in various environments such as soil, water, and food products like meat and dairy. They are also present in meat processing environments, including beef slaughterhouses and boning lines. Some of the psychrophilic microorganisms identified in these environments include Candida zeylanoides, Rhodotorula sp., Pseudomonas sp., and Rhodococcus sp.. Psychrophilic microorganisms have unique biological features that make them suitable for use in various biotechnological industries, including pharmaceuticals, enzyme production, bioremediation, biosensors, cosmetics, agriculture, and textile industry. They are also recognized as a potential source of cold-active enzymes and bioactive compounds, which have higher catalytic activity at low temperatures compared to mesophilic enzymes. Additionally, probiotics such as Lactobacillus casei, Lactobacillus dulbrueckii, and Bifidobacterium lactis have been found to have an antimicrobial effect against psychrotrophic bacteria in meat, including pseudomonas and aeromonas.
What are some examples of psychrotrophic bacteria?5 answersPsychrotrophic bacteria are a group of microorganisms that can grow at low temperatures. Examples of psychrotrophic bacteria mentioned in the abstracts include Carnobacterium maltaromaticum, Carnobacterium divergens, Brocothrix thermosphacta, Lactobacillus curvatus, Lactobacillus brevis, Enterobacter kobei, Serratia ureilytica, Aerococcus urinaeequi, Bacillus licheniformis, Acinetobacter lwoffii, Pseudomonas spp., and Yersinia enterocolitica. These bacteria have the ability to produce enzymes such as exoproteases and lipases, which can degrade proteins and lipids, respectively, and contribute to the spoilage of food products, including poultry, milk, and dairy products. Additionally, the abstracts mention the presence of psychrotrophic microorganisms in frozen fishand in cryopegs, which are hypersaline unfrozen soil or water within permafrost.