Growth Characteristics of Brevibacterium , Corynebacterium , Microbacterium , and Staphylococcus spp. Isolated from Surface-Ripened Cheese

Abstract

The growth characteristics of five bacteria, Brevibacterium aurantiacum 1-16-58, Corynebacterium casei DPC 5298 T , Corynebacterium variabile DPC 5310, Microbacterium gubbeenense DPC 5286 T , and Staphylococcus saprophyticus 4E61, all of which were isolated from the surface of smear cheese, were studied in complex and chemically defined media. All of the coryneforms, except M. gubbeenense, grew in 12% salt, while B. aurantiacum and S. saprophyticus grew in 15% salt. All five bacteria assimilated lactate in a semisynthetic medium, and none of the coryneform bacteria assimilated lactose. Glucose assimilation was poor, except by S. saprophyticus and C. casei. Five to seven amino acids were assimilated by the coryneforms and 12 by S. saprophyticus. Glutamate, phenylalanine, and proline were utilized by all five bacteria, whereas utilization of serine, threonine, aspartate, histidine, alanine, arginine, leucine, isoleucine, and glycine depended on the organism. Growth of C. casei restarted after addition of glutamate, proline, serine, and lactate at the end of the exponential phase, indicating that these amino acids and lactate can be used as energy sources. Pantothenic acid was essential for the growth of C. casei and M. gubbeenense. Omission of biotin reduced the growth of B. aurantiacum, C. casei, and M. gubbeenense. All of the bacteria contained lactate dehydrogenase activity (with both pyruvate and lactate as substrates) and glutamate pyruvate transaminase activity but not urease activity.Bacterial surface-ripened cheeses are characterized by the development of a viscous, red-orange smear on the surface composed of yeasts, mainly Debaryomyces hansenii and Geotrichum candidum, and gram-positive bacteria such as coryneforms and staphylococci (10). Because of its tolerance to high salt concentrations and low pH, D. hansenii develops first on the cheese, metabolizing lactate to CO 2 and H 2 O and forming alkaline metabolites, such as ammonia, that lead to deacidification of the cheese surface, enabling the growth of the salttolerant but less-acid-tolerant bacteria.Until recently, Brevibacterium linens was considered to be the major component of the surface microflora, and most of the research on smear cheese bacteria has focused on physiological and growth characteristics either in liquid cultures (13,14,31,32), on experimental cheeses in mixed cultures with D. hansenii (25-27), or on cheese agar (30). During the last few years, the microflora of several smear cheeses has been extensively investigated and categorically identified using combinations of phenotypic and genotypic techniques (9,15,29,33,42 (22,33). Recently, S. saprophyticus has been shown to dominate the surface of Gubbeen cheese early in ripening but is then replaced by corynebacteria, particularly C. casei (38).Strains of B. linens and D. hansenii from commercial laboratories are generally inoculated onto the cheese surface early in ripening, but their subsequent recovery during ripening is very low (39) or absent (34), indicating that an adventitious...

Degradation of Sulfadiazine by Microbacterium lacus Strain SDZm4, Isolated from Lysimeters Previously Manured with Slurry from Sulfadiazine-Medicated Pigs

“…T (38). However, once cultivated in pure culture without competing fast-growing bacterial contaminants, the M. lacus SDZm4 strain isolated in this study was easily culturable in nonselective complex medium.…”

“…Microbacteria are widely distributed in many environments (32), namely, marine sediments (33), compost (34), activated sludge (35), wastewater (36), infected human blood (37), cheese (38), arable soils (29; this study), and many more. Accordingly, Microbacterium species are involved in diverse biodegradation reactions and in oxidation and reduction reactions (32,36).…”

Tryptophan-containing milk protein-derived dipeptides inhibit xanthine oxidase

“…Free amino acids were quantified (Trp, Gln and Asn not determined) as per Mounier et al [62]. Relatively low amounts of free amino acids were 13 released in the hydrolyzates with values of 0.22, 0.08 and 0.46 g/100g determined in PLF-240 min, GLF-240 min and GPLF-240 min, respectively.…”

Temporal and Spatial Differences in Microbial Composition during the Manufacture of a Continental-Type Cheese

“…Brevibacterium and Corynebacterium were identified immediately postproduction and are associated with flavor and color development in smear-ripened cheese (22,(57)(58)(59). Arthrobacter, Weissella, and Acinetobacter, previously isolated from a variety of artisanal cheeses, were also identified, although their impact on cheese quality is unknown (60)(61)(62)(63)(64)(65)(66)(67).…”