Lactobacillus amylovorus, a New Starch-Hydrolyzing Species from Cattle Waste-Corn Fermentations

Abstract

Several starch-hydrolyzing strains of Lactobacillus Beijerinck 1901 were isolated from cattle waste-corn fermentations. The isolates were facultatively anaerobic, gram-positive, nonmotile, nonsporeforming, rod-shaped organisms that grew singly and in short chains, produced lactic acid and small amounts of acetic acid but no gas from glucose, and did not exhibit oxidase-, catalase-, or nitrate-reducing activities. Growth occurred at 45°C but not at 15°C. m-Lactic acid was synthesized from glucose. An extracellular amylolytic enzyme was formed. The organisms fermented amygdalin, cellobiose, esculin, fructose, galactose, glucose, maltose, mannose, salicin, starch, sucrose, and trehalose. Some strains fermented mannitol and lactose. Arabinose, gluconate, melezitose, melibiose, raffinose, rhamnose, ribose, and xylose were not fermented. The average guanine-plus-cytosine content of the deoxyribonucleic acid was 40.4 mol%. Reassociation values of 15% or less were obtained with the deoxyribonucleic acids of the starch hydrolyzers and those of the type strains of Lactobacillus acidophilus (Moro) Hansen and Mocquot 1970; Lacto bacillus jensenii Gasser, Mandel, and Rogosa 1970; and Lactobacillus leichmanii (Henneberg) Bergey et al. 1923. The new species was differentiated from the three recognized species on the basis of starch fermentation, vitamin requirements, guanine-plus-cytosine contents, and stereoisomerism of lactic acid produced. It was concluded that these organisms represent strains of a hitherto unrecognized species for which the name Lactobacillus amylouorus is proposed. The type strain of L. amylouorus is NRRL B-4540. Studies at the Northern Regional ResearchCenter demonstrated that lactobacilli are the predominant bacteria involved in cattle wastecorn fermentations (12). The principal Lactobacillus species identified were L. buchneri, L. ferrnentum, L. plantarum, L. casei, and L. delbrueckii. By the use of LBS (Lactobacillus selection) agar (29) enriched with 1% corn starch, it was revealed that of the presumed lactobacilli enumerated some were capable of hydrolyzing starch (13). Because active starch metabolism is a characteristic not commonly exhibited by lactobacilli, the following questions concerning the taxonomic position of these starch hydrolyzers were raised. (i) Were these organisms unusual strains of presently recognized Lacto bacillus species? (ii) Were they strains of hitherto unrecognized Lacto bacillus species? (iii) Were they other starch-hydrolyzing bacteria capable of growing on LBS agar?The present study was undertaken to characterize the starch hydrolyzers and to determine their taxonomic status. The results indicate that the organisms represented strains of a new Lacto bacillus species. MATERIALS AND METHODSBacterial strains. Twelve starch-hydrolyzing isolates from cattle waste-corn fermentations (

Identification of lactobacilli by pheS and rpoA gene sequence analyses

“…The pheS and rpoA partial gene sequences revealed heterogeneity among culture collection strains of L. amylophilus described by Nakamura & Crowell (1979). Strains LMG 11400 and NRRL B-4435 represent a separate lineage that is distantly related to the type strain of L. amylophilus LMG 6900 T and to three other strains of the species (NRRL B-4438, NRRL B-4439 and NRRL B-4440).…”

Utilization of Lactobacillus amylovorus as an Alternative Microorganism for Saccharifying Boiled Rice.

“…The fluid saccharified by the lactic acid bacterium contained soluble starch, oligosaccharides, and lactose, which may cause slight sweetness. Because L. amylovorus cannot ferment lactose (Nakamura, 1981), lactose included in skim milk was not consumed.…”

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Cyclodextrin glycosyltransferase biosynthesis improvement by recombinantLactococcus lactisNZ:NSP:CGT: medium formulation and culture condition optimization

“…Starch-iodine assay was employed to measure the starch concentration in the samples. [27] An appropriately diluted sample (1 mL) was mixed with 0.1 mL of iodine solution (0.2 g of I 2 and 2.0 g of KI in 100 mL of distilled water). The mixture was then filled up to 10 mL using distilled water and the absorbance was measured at 590 nm.…”