• Korean Journal of Microbiology
• /
• v.38 no.2
• /
• pp.57-61
• /
• 2002

To investigate the characteristics of carbon sources utilization by the intestinal microflora of starfish, starfishes (Asterias amurensis) were collected from the South Sea near Jangheung-gun sumun-ri of Jeollanam-do on July 14,2000. The population densities of heterotrophic bacteria were in the range of $8.65{\pm}0.65{\times}10^3\cfu{\cdot}g^{-1}$ in the interval organs of starfish. Total 24 strains (Gram-negative bacteria. 11 strains, Gram-positive bacteria: 13 strains) from the internal organs of starfish were isolated. Dominant bacteria were Genus nbrio, Staphylococcus, and Corynebacterium. A high percentage of isolates was Gram positive rods. The catalase and oxidase positive were shown 54.2% and 20.8% of isolated bacteria, respectively. Isolated Gram negative and positive bacteria utilized various carbon sources. Among them, glucose could be utilized by all the isolated Gram negative bacteria, and sucrose, mannose, and maltose were utilized by a relatively high percentage of isolates. On the other hands, adipate and phenyl acetate were shown no utilization. In case of Gram positive bacteria, glucose was shown the highest utilization and the next highest utilization was fructose, trehalose, and maltose.

• Microbiology and Biotechnology Letters
• /
• v.24 no.4
• /
• pp.385-392
• /
• 1996

Bacillus stearotheymophilus, a potent xylanolytic bacterium isolated from soil, was tested for the strain's strategies of pentose utilization and the evidence of substrate preferences. The strain metabolized glucose, xylose, ribose, maltose, cellobiose, sucrose, arabinose and xylitol. The efficacy of the sugars as a carbon and energy source in this strain was of the order named above. The organism, however, could not grow on glycerol as a sole growth substrate. During cultivation on a mixture of glucose and xylose or arabinose, the major hydrolytic products of xylan, B. stearothermophilus displayed classical diauxic growth in which glucose was utilized during the first phase. On the other hand, the pentose utilization was prevented immediately upon addition of glucose. Cellobiose was preferred over xylose or arabinose. In contrast, maltose and pentose were co-utilized, and also no preference on between xylose and arabinose. Enzymatic studies indicated that B. stearothermophilus possessed constitutive hexokinase, a key enzyme of the glucose metabolic system. While, the production of $^{D}$-xylose isomerase, $^{D}$-xylulokinase and $^{D}$-arabinose isomerase essential for pentose phosphate pathway were induced by xylose, xylan, and xylitol but repressed by glucose. Taken together, the results suggested that the sequential utilization of B. stearothermophilus would be mediated by catabolite regulatory mechanisms such as catabolite inhibition or inducer exclusion.

• Korean Journal of Microbiology
• /
• v.25 no.4
• /
• pp.360-366
• /
• 1987

For the production of pullulan from the high concentration of sugar, the utilization of sugars by a pullulan-producing fungus, Aureobasidium pullulans was examined. A. pullulans showed the different utilization patterns for sugars such as sucrose, maltose, and maltotriose. Especially for maltotriose, the hydrolysis of sugar was accompanied by a transferase activity. Glucose and maltose showed the inhibitory effect on the cell growth and the pullulan production at the sugar concentration higher than 0.28M, but sucrose showed the inhibitory effect at the sugar concentration higher than 0.14M. Among the sugars examined, sucrose gave the best result for the pullulan production. 27.5g/l of pullulan was obtained from 5% sucrose.

• Journal of Plant Biology
• /
• v.6 no.4
• /
• pp.1-4
• /
• 1963

Using conidia of Neurospora, changes in respiratory activities and the sensitivity to the ultraviolet light of the cells at different growing stages were measured by manometric methods, and the correlation between them was observed. Efficiency in the utilization of various carbon sources, such as, glucose, sucrose, maltose, starch and sodium acetate, in growth and exogenous respiration of N. crassa was also determined. Growth rate of N. crassa was decreased considerably in the medium containing sodium acetate than in the glucose medium and was almost zero in the lactose medium, whereas the utilization of sucrose, maltose and starch was ve교 high, as that of glucose. Respiratory activities of the cells veried considerably depending upon their different growing stages. Actively growing hyphae exhibited the greatest activity in exogenous glucose respiration, followed by germinating and activated conidia in decreasing order. There was no proportional relationship between the dose of ultraviolet light irradiated and its effect on the respiratory activity of the cells, though the more the dose of ultraviolet light, the more the injury. The sensitivity of the cells to ultraviolet light varied with the different respiratory activities of the cells linked to the developmental stages. In general, the more actively growing cells having high respiratory activities exhibited the more serious injury.

• Mycobiology
• /
• v.39 no.1
• /
• pp.33-39
• /
• 2011

Wild yeasts on the surface of various fruits including grapes were surveyed to obtain yeast strains suitable for fermenting a novel wine with higher alcohol content and supplemented with rice starch. We considered selected characteristics, such as tolerance to alcohol and osmotic pressure, capability of utilizing maltose, and starch hydrolysis. Among 637 putative yeast isolates, 115 strains exhibiting better growth in yeast-peptone-dextrose broth containing 30% dextrose, 7% alcohol, or 2% maltose were selected, as well as five ${\alpha}$-amylase producers. Nucleotide sequence analysis of the 26S rDNA gene classified the strains into 13 species belonging to five genera; Pichia anomala was the most prevalent (41.7%), followed by Wickerhamomyces anomalus (19.2%), P. guilliermondii (15%), Candida spp. (5.8%), Kodamaea ohmeri (2.5%), and Metschnikowia spp. (2.5%). All of the ${\alpha}$-amylase producers were Aureobasidium pullulans. Only one isolate (NK28) was identified as Saccharomyces cerevisiae. NK28 had all of the desired properties for the purpose of this study, except ${\alpha}$-amylase production, and fermented alcohol better than commercial wine yeasts.

• Journal of Microbiology and Biotechnology
• /
• v.15 no.3
• /
• pp.616-625
• /
• 2005

It is likely that maltose could provide a good substrate for the bacteria in the intestine, when the pathogenic bacteria invade and colonize in human gut. For better understanding of this organism's maltose metabolism, a mutant that was not able to grow with maltose as a sole carbon source was screened from a library of mutants constructed by a random transposon mutagenesis. By a transposon-tagging method, malPQ genes encoding a maltodextrin phosphorylase and a 4-${\alpha}$-glucanotransferase, were identified and cloned from Vibrio vulnificus. The deduced amino acid sequences of malPQ from V. vulnificus were 48 to $91\%$ similar to those of MalP and MalQ reported from other Enterobacteriaceae. Functions of malPQ genes were assessed by the construction of mutants whose malPQ genes were inactivated by allelic exchanges. When maltose was used as the sole carbon source, neither malP nor malQ mutant was able to grow to a substantial level, revealing that the MalP and MalQ are the only enzymes for metabolic utilization of maltose. The malQ mutant exhibited decreased adherence toward intestinal epithelial cells in vitro, but there was no difference in the $LD_{50}s$ of the wild-type and the malQ mutant in mice. Therefore, it appears that MalQ is less important in the pathogenesis of V. vulnificus than would have been predicted by considering maltose as a most common sugar in the intestine, but not completely dispensable for virulence in mice.

• Korean Journal of Food Science and Technology
• /
• v.10 no.4
• /
• pp.423-430
• /
• 1978

Since 1950 there has been a dramatic progress in rationalization of the production of sweet potato and potato starch in Japan. This enabled dextrose industry by enzymatic process to develop rapidly due to the success of enzymatic liquefaction and saccharification. Isomerization of glucose to fructose has been studied, and the immobilization of isomerases prompted its products on industrial scale in 1970. Another advance is the development of effective methods of producing high purity maltose. A malto-hexaose forming amylase was discovered in 1971 and attempts are being made for its pharmaceutical utilization. Saccharification of cellulose by cellulase has been studied. Conversion of starch to other polysaccharides is another example for the numerous Japanese activities.

• Journal of Microbiology
• /
• v.42 no.4
• /
• pp.319-327
• /
• 2004

An additional amylase, besides the typical $\alpha-amylase,$ was detected for the first time in the cytoplasm of B. subtilis SUH4-2, an isolate from Korean soil. The corresponding gene (bbmA) encoded a malto­genic amylase (MAase) and its sequence was almost identical to the yvdF gene of B. subtilis 168, whose function was unknown. Southern blot analysis using bbmA as the probe indicated that this gene was ubiquitous among various B. subtilis strains. In an effort to understand the physiological function of the bbmA gene in B. subtilis, the expression pattern of the gene was monitored by measuring the $\beta-galactosidase$ activity produced from the bbmA promoter fused to the amino terminus of the lacZ struc­tural gene, which was then integrated into the amyE locus on the B. subtilis 168 chromosome. The pro­moter was induced during the mid-log phase and fully expressed at the early stationary phase in defined media containing $\beta--cyclodextrin\;(\beta-CD),$ maltose, or starch. On the other hand, it was kept repressed in the presence of glucose, fructose, sucrose, or glycerol, suggesting that catabolite repression might be involved in the expression of the gene. Production of the $\beta-CD$ hydrolyzing activity was impaired by the spo0A mutation in B. subtilis 168, indicating the involvement of an additional regu­latory system exerting control on the promoter. Inactivation of yvdF resulted in a significant decrease of the $\beta-CD$ hydrolyzing activity, if not all. This result implied the presence of an additional enzyme(s) that is capable of hydrolyzing $\beta-CD$ in B. subtilis 168. Based on the results, MAase encoded by bbmA is likely to be involved in maltose and $\beta-CD$ utilization when other sugars, which are readily usable as an energy source, are not available during the stationary phase.

• Microbiology and Biotechnology Letters
• /
• v.44 no.3
• /
• pp.363-369
• /
• 2016

A putative cyclomaltodextrinase gene (licd) was found from the genome of Listeria innocua ATCC 33090. The licd gene is located in the gene cluster involved in maltose/maltodextrin utilization, which consists of various genes encoding maltose phosphorylase and sugar ABC transporters. The structural gene encodes 591 amino acids with a predicted molecular mass of 68.6 kDa, which shares less than 58% of amino acid sequence identity with other known CDase family enzymes. The licd gene was cloned, and the dimeric enzyme with C-terminal six-histidines was successfully produced and purified from recombinant Escherichia coli. The enzyme showed the highest activity at pH 7.0 and 37℃. licd could hydrolyze β-cyclodextrin, starch, and maltotriose to mainly maltose, and it cleaved pullulan to panose. It could also catalyze the hydrolysis of acarbose to glucose and acarviosine-glucose. In particular, it showed significantly higher activity towards β-cyclodextrin and maltotriose than towards starch and acarbose. licd also showed transglycosylation activity, producing α-(1,6)- and/or α-(1,3)-linked transfer products from the acarbose donor and α-methyl glucopyranoside acceptor.

• Korean Journal of Microbiology
• /
• v.29 no.3
• /
• pp.184-188
• /
• 1991

Three strains of Clostridium thermocellum, JH01, JH20 and JH30 which are capable of producing ethanol directly from cellulose were isolated from composts. The morphological, cultural and physiological properties of the strains were similar to the ATCC type strain, except for carbon source utilization and degree of ethanol tolerance. All of the three isolates could use glucose and maltose as a sole carbon source and two of them, strains of JH01 and JH20 were three times more tolerant to ethanol than the ATCC type strain. Cellulases secreted by the isolated strains had higher activities than those of the ATCC type strain.