LIPOLYTIC ACTIVITY OF MICROORGANISMS AT LOW AND INTERMEDIATE TEMPERATURES. I. ACTION OF <i>PSEUDOMONAS FLUORESCENS</i> ON LARD<sup>a</sup>

Alford, John A.; Elliott, Lisa

doi:10.1111/j.1365-2621.1960.tb00334.x

Cited by 47 publications

(26 citation statements)

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“…A similar procedure was used for G. candidunz and C. lipolytica except that citrate buffer at pH 5.0 was used. Previous work (Alford and Elliott, 1960;Morris and Jezeski, 1953;Peters and Nelson, 1948) as well as additional observations in our laboratory indicated that assays at these pH values would give near-optimum activity.…”

mentioning

confidence: 86%

“…Substrate preparation. The lard, corn oil, and coconut oil emulsions were prepared as previously described (Alford and Elliott, 1960) except that homogenization was carried out at 4000-4500 lb with a recycling period of 15 min, and the emulsions were not heated after preparation. Phosphate buffer at pH 7.0 was added to the emulsions to be used for the lipases from P. fluorescens, S. aureus, and the two molds so that the final concentration after addition of enzyme would be 0.05M buffer and 2% fat.…”

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confidence: 99%

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Lipolytic Activity of Microorganisms at Low and Intermediate Temperatures. III. Activity of Microbial Lipases at Temperatures Below 0°C

Alford

Pierce

1961

Journal of Food Science

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SUMMARY The lipolytic activity at ‐7, ‐18, and ‐29°C of strains of Pseudomonas fragi, Staphylococcus aureus, Geotrichum candidum, Candida lipolytica, Penicillium roqueforti, and an unidentified Penicillium sp. in emulsions of corn oil, coconut oil, and lard was determined. The action was measured by titratable acidity and by quantitative determination of the fatty acids by chromatography. The lipases from these microorganisms showed considerable activity within 2‐4 days at ‐7°C and within a week at ‐18°C. Activity at ‐29°C was evident within 3 weeks by some of the cultures, particularly on corn oil. The rate of lipolysis in frozen substrates was directly related to their degree of unsaturation. However, there also were differences among genera. The lipase of G. candidum had considerably more specificity for oleic and linoleic acids than any of the others. P. fragi and C. lipolytica were least able to attack the β‐esterified palmitic acid of lard. The ability of S. aureus to attack this position readily at 35° C was nullified by lowering the temperature to –18° C. A similar effect was observed on the mold lipase.

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confidence: 86%

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confidence: 99%

Lipolytic Activity of Microorganisms at Low and Intermediate Temperatures. III. Activity of Microbial Lipases at Temperatures Below 0°C

Alford

Pierce

1961

Journal of Food Science

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“…Production of the metalloprotease AprX begins at the early stages of bacterial growth cycle at refrigerated temperatures. A study assessing the lipolytic activity of spoilage pseudomonads at low temperatures has shown that the amount of enzyme produced per cell at 5 °C was equal to that produced at 20 °C (Alford & Elliott, ). Similar results were reported in a more recent study that assessed the lipase activity of P. fluorescence strain SMD 31.…”

Section: Dominance Of Meat Spoilage Pseudomonads On Aerobically Storementioning

confidence: 99%

The Predominance of Psychrotrophic Pseudomonads on Aerobically Stored Chilled Red Meat

Wickramasinghe

Ravensdale

Coorey

et al. 2019

Comp Rev Food Sci Food Safe

101

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Microbial spoilage of meat during chilled aerobic storage causes significant financial losses to the industry. Even with modern day preservation techniques, spoilage remains an unsolved problem. Spoilage of meat is a complex process that involves the activity of endogenous enzymes and microorganisms. Psychrotrophic Pseudomonas species are the key microorganisms that cause spoilage in aerobically stored chilled meat. Spoilage pseudomonads are highly robust and able to withstand stressful environmental conditions that would otherwise inhibit the growth of other spoilage organisms. In order to implement efficient control measures, and to minimize spoilage, a thorough understanding of the characteristics of spoilage pseudomonads is essential. This review focuses on the spoilage process and the key metabolic attributes of the main psychrotrophic spoilage Pseudomonas species to explain their predominance on meat over other psychrotrophic bacteria. This review also highlights less studied, but important, characteristics of psychrotrophic pseudomonads such as biofilm formation and quorum sensing in the context of meat spoilage. The importance of the use of model systems that are closely applicable to the food industry is also discussed in detail.

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“…With respect to individual groups of enzymes, yields of endocellular proteolytic enzymes are greater in Pseudomonas fluorescens grown at lOoe than at either 20°C or 35°C, (52), whereas other investigators have shown that P. tragi preferentially produces lipase at low temperatures, with none being produced at 30°C or higher (48,49). P. fluorescens has been found to produce just as much lipase at 5°C as at 20°C, but only a slight amount was produced at 30°C (1). On the other hand, a proteolytic enzyme system of P. fluorescens showed more activity on egg white and hemoglobin at 25°C than at 15°C and 5°C (27).…”

Section: The Effect Of Low Temperatures On Microbial Physiologic Mechmentioning

confidence: 99%

Low-Temperature Food Preservation and Characteristics of Psychrotrophic Microorganisms

Jay

1998

Modern Food Microbiology

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The use oflow temperatures to preserve foods is based on the fact that the activities of foodborne microorganisms can be slowed at temperatures above freezing and generally stopped at subfreezing temperatures. The reason is that all metabolic reactions of microorganisms are enzyme catalyzed and that the rate of enzyme-catalyzed reactions is dependent on temperature. With a rise in temperature, there is an increase in reaction rate. The temperature coefficient (Q10) may be generally defined as follows: Q _ (Velocity at a given temp. + lOOe) 10 - Velocity at TThe QlO for most biological systems is 1.5-2.5, so that for each lOoe rise in temperature within the suitable range, there is a twofold increase in the rate of reaction. For every 10 0 e decrease in temperature, the reverse is true. Because the basic feature of lowtemperature food preservation consists of its effect on spoilage organisms, most of the discussion that follows will be devoted to the effect of low temperatures on foodborne microorganisms. It should be remembered, however, that temperature is related to relative humidity (R.H.) and that subfreezing temperatures affect R.H. as well as pH, and possibly other parameters of microbial growth as well. DEFINITIONSThe term psychrophile was coined by Schmidt-Nielsen in 1902 for microorganisms that grow at ooe (30). This term is now applied to organisms that grow over the range of subzero to 20 o e, with an optimum range of 10-15°e (44). Around 1960, the term psychrotroph (psychros, "cold," and trephein, "to nourish" or "to develop") was suggested for organisms able to grow at 5°e or below (11, 47). It is now widely accepted 328 J. M. Jay, Modern Food Microbiology

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LIPOLYTIC ACTIVITY OF MICROORGANISMS AT LOW AND INTERMEDIATE TEMPERATURES. I. ACTION OF PSEUDOMONAS FLUORESCENS ON LARD^a

Cited by 47 publications

References 15 publications

Lipolytic Activity of Microorganisms at Low and Intermediate Temperatures. III. Activity of Microbial Lipases at Temperatures Below 0°C

Lipolytic Activity of Microorganisms at Low and Intermediate Temperatures. III. Activity of Microbial Lipases at Temperatures Below 0°C

The Predominance of Psychrotrophic Pseudomonads on Aerobically Stored Chilled Red Meat

Low-Temperature Food Preservation and Characteristics of Psychrotrophic Microorganisms

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LIPOLYTIC ACTIVITY OF MICROORGANISMS AT LOW AND INTERMEDIATE TEMPERATURES. I. ACTION OF PSEUDOMONAS FLUORESCENS ON LARDa

Cited by 47 publications

References 15 publications

Lipolytic Activity of Microorganisms at Low and Intermediate Temperatures. III. Activity of Microbial Lipases at Temperatures Below 0°C

Lipolytic Activity of Microorganisms at Low and Intermediate Temperatures. III. Activity of Microbial Lipases at Temperatures Below 0°C

The Predominance of Psychrotrophic Pseudomonads on Aerobically Stored Chilled Red Meat

Low-Temperature Food Preservation and Characteristics of Psychrotrophic Microorganisms

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LIPOLYTIC ACTIVITY OF MICROORGANISMS AT LOW AND INTERMEDIATE TEMPERATURES. I. ACTION OF PSEUDOMONAS FLUORESCENS ON LARD^a