• Microbiology and Biotechnology Letters
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• v.44 no.4
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• pp.563-570
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• 2016

Two Streptomyces griseus strains, a wild-type strain and an A-factor-dependent transcriptional activator mutant strain harboring multiple copies of a gene, dasA, that encodes a substrate-binding protein of the ATP-binding cassette transporter, showed severe ectopic sporulation of young substrate hyphae in response to glucose. The effect of dasA overexpression on the ectopic sporulation of Streptomyces strains was evaluated by comparing the transcriptomes of the strain harboring multiple copies of dasA and a strain harboring empty vector. By DNA microarray, 4 genes (SGR794, SGR2469, SGR3656, and SGR3657) and 3 clusters (SGR795-797, SGR2377-2378, and SGR6997-6998) were differentially expressed by more than 2-fold in S. griseus strains harboring dasA. The DNA microarray result was validated by low-resolution S1 nuclease mapping.

• Mycobiology
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• v.33 no.4
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• pp.215-222
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• 2005

Variability in growth and sporulation of five isolates of Arthrobotrys dactyloides was studied on five agar, 6 bran and 5 grain media. Potato dextrose agar (PDA) supported maximum growth of isolate A, C and E, while growth of isolate Band D was significantly lower on this medium. On Czapek's agar and yeast glucose agar media the differentiation in the isolates in relation to growth was poor than PDA. The other two media showed much poorer differentiation. On Czapek's agar medium, sporulation was recorded in isolate B only, whereas other isolates showed rare sporulation. Among the bran media, pea bran agar medium supported maximum growth of all the isolates except isolate B. Gram and rice bran agar media were next best. However, the growth of isolate B on the gram bran agar medium was more or less equal as other isolates. On pigeon pea bran agar medium, isolate E failed to grow while other isolates recorded poor growth. On lentil bran agar medium, only isolate Band D recorded little growth, whereas other isolates failed to grow. All the isolates recorded good sporulation on bran agar media except pigeon pea and lentil bran agar media. The grain agar media supported moderate to very good growth of all the isolates. In general isolate B remained slow growing on these media except gram grain and sorghum grain agar media on which growth of this isolate was comparable to other isolates. Sporulation in general, was good on all the grain agar media. Among different substrates screened, barley grain and pea bran were found superior to others for mass culture of isolate A of A. dactyloides.

• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.568-572
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• 2005

Saccharomyces yeast spores are more resistant to drying and storage than vegetative cells. For the mass production of yeast spores, compressed yeast was directly inoculated into a sporulation medium (SM). The effects of inoculum size and the addition of rice wine cake (RWC) into SM on the sporulation were examined using flasks. With $1\%$ inoculum of compressed yeast, $1.45{\times}10^8/ml$ of asci was obtained. The addition of $0.5\%$ RWC into SM improved the cell growth and spore yield, and the number of asci formed was $2.31{\times}10^8/ml$. The effects of culture temperature, temperature-shift, and concentrations of inoculum, potassium acetate, and RWC on the sporulation were also evaluated using a jar fermentor. The optimum temperature for spore formation was $22^{\circ}C$ where the number of asci formed was $2.46{\times}10^8/ml$. The shift of culture temperature from initial $30^{\circ}C$ for 1 day to $22^{\circ}C$ for 3 days increased the number of asci formed to $2.96{\times}10^8/ml$. The use of $2\%$ (w/v) inoculum of compressed yeast, $2\%$ potassium acetate, and $1\%$ (w/v) RWC in SM with the shift of culture temperature of initial $30^{\circ}C\;to\;22^{\circ}C$ resulted in $90\%$ sporulation ratio and formation of $6.18{\times}10^8\;asci/ml$.

• Mycobiology
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• v.31 no.4
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• pp.221-225
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• 2003

Effect of ethanolic extracts of Lawsonia inermis, Azadirachta indica, Vinca rosea, Tagetes patula, Ocimum sanctum, Colocasia antiquorum, Adhatoda vasica, Moringa oleifera, Datura metel and Curcuma longa leaf on conidial germination, mycelial growth and sporulation of Aspergillus flavus, A. niger and A. fumigatus were examined. The conidial germination of A. flavus and A. fumigatus were most inhibited by the extract of L. inermis, while that of A. niger was inhibited by A. indica. Other tested plant extracts have a good effect on conidial germination on the selected fungi. The highest mycelial growth of A. flavus(37 mm) was found in V. rosea, but in case of A. niger and A. fumigatus it(38 and 39 mm) was found in D. metel. The lowest(4, 9 and 6 mm) respectively mycelial growth of these fungi found in L. inermis. The highest sporulation($75{\times}10^4/ml$) of A. flavus was counted in V. rosea, but in case of A. niger and A. fumigatus those($45{\times}10^4$ and $55{\times}10^4/ml$) were in D. metel and the lowest($5{\times}10^4,\;12{\times}10^4\;and\;9{\times}10^4/ml$) respectively sporulation of these fungi counted in L. inermis plant extract medium.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.1
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• pp.85-93
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• 2011

The structural components of microorganism are quite related to the toxin and environmental conditions. The vegetative and dormant cells are quite affected by the physical and chemical environments to survive and they will be dormant when they are in the extreme environment. The mechanism to activate the microorganisms however, is not well defined yet in the area of activation state and sporulation state through the analysis of EPS. Other than that even the main mechanism of prior to acquisition of analysis values is not well understood. Therefore, what kind of specific environment to affect the activation and sporulation will be discussed through the analysis of the extracellular polymeric substances(EPS). EPS are a high molecular weight mixture of polymers presenting both outside of cells and interior of microbial aggregates. They are a major complex materials in microbial aggregation for sustaining them together in a three dimensional matrix. Three commonly used extraction methods were applied to this study their effectiveness and quantification in extracting EPS from several Bacillus microorganisms and activated sludge. Three extraction methods used for this study are regular centrifugation with formaldehyde (RCF), Steaming, and EDTA extraction. The results of EPS contents such as the quantitative proteins, carbohydrates and the ratio of protein versus carbohydrate from the several species with the several specific methods showed in this research. This study aims to get comparable results of the quantitative production of EPS and the effectiveness of sedimentation for Bacillus microorganisms and activated sludge from several wastewater treatment plans. The results revealed that the protein amount extracted was the highest by the Steaming method of three extraction methods before sporulation and the carbohydrate amount extracted was the highest by the RCA method of three extraction methods after sporulation. The higher amount of protein compared with carbohydrate from Bacillus microorganisms affected higher sedimentation efficiency, however it could not be found the relation between the EPS production and sedimentation efficiency for the activated sludge.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.263-268
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• 2002

Bacillus polyfermenticus SCD, which is commonly called a 'Bisroot' strain, has been appropriately used for the treatment of long-term intestinal disorders, since the live strains, in the form of active endospores, can successfully reach the target intestine. Goal of this study was to develop an industrial medium for growth and sporulation of B. polyfermenticus SCD. From the results of effect of mixed carbon sources on growth and sporulation of B. polyfermenticus SCD, glucose 2% and starch 2% was particularly found to be the most effective for the maximum number of spore production, resulting in spore cells of $4.3{\times}10^9\;spores/mL$ with a sporulation yield of 91%. For the effect of nitrogen sources, the maximum spore cells of $5.7{\times}10^9\;spores/mL$ of B. polyfermenticus SCD with a sporulation yield of 97% was obtained when B. polyfermenticus SCD was cultivated in an optimum nitrogen source medium containing 5% soybean flour. A medium involving proper phosphate salt yielded the maximum number of a spore cells of $6.0{\times}10^9\;spores/mL$ with a sporulation yield of 95%. Finally, the efficacy of an industrial medium (KH5 medium) on growth and sporulation of B. polyfermenticus SCD was investigated in jar fermenter. The higher number of viable cells $(3.3{\times}10^{10}\;cells/mL)$ and spore cells $(3.0{\times}10^{10}\;spores/mL)$ were obtained in 5 L fermenter when compared with a 500 mL baffle flask cultivation. Thus, KH5 medium developed in this study shows promise as an industrial medium because of higher cells and sporulation yield.

• The Korean Journal of Mycology
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• v.10 no.4
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• pp.187-192
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• 1982

The effects of amino acids on mycerial growth and sporulation of the decreased and increased pathogenicity variants of potato dry rot Fusarium roseum ‘Sambucinum' were as following. The increased pathogenicity variants Ic52 and Ic116 showed the trend of greater mycerial growth, marking up to 67mg on leucine, than the decreased pathogenicity variants Dc14 and Dc91, and produced markedly low conidia below $25{\times}10^{4}/ml$ or no sporulation. On methionine all the variants and the wild type showed the lowest growth recording 14mg to 20mg with no sporulation. Cystine similarly as glysine supported the poor growth 30mg to 19mg of the variants Dc14 and Dc91, respectively, and did not support the sporulation. The former amino acid like asparagine supported the growth of the variants Ic52 and Ic1l6 marking 47mg and 36mg, respectively. On all the eleven amino acids the variant Dc14 showed the trend of more mycerial growth and sporulation than the variant Dc91 which marked the exceptionally high sporulation $195{\times}10^{4}/ml$ on glutamic acid.

• KSBB Journal
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• v.26 no.3
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• pp.229-236
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• 2011

An efficient screening method was developed for rapid selection of a few overproducers of itaconic acid (IA) among the great many mutants derived from mother strains of Aspergillus terreus. For this purpose, an attempt was made to reveal the relationships of the growth rate and sporulation of each mutant on PDA solid medium with its IA productivity in the final liquid production-culture. As a result, it was possible to classify the mutated strains into 5 groups (from [A] to [E] group) according to theirmorphologies (i.e., growth rate and sporulation extent) on the PDA slants. Notably, most of the high-yielding mutants of IA were observed to belong to [A]group which had the properties of the highest growth rate and sporulation among the 5 groups, whereas the mutant groups of [C], [D] and [E] with the contrasting morphological features showed significant reductions in their IA productivities. From these results, it was concluded that the probability of selecting IA overproducing mutants could be remarkably enhanced when the mutated colonies showing faster growth rates are firstly selected on the PDA plate, and then further screening process is performed on the basis of the sporulation extents of the mutants selected. Consequently, through the application of the strategy developed in this study, costs and time involvedin the labor-intensive task of strain improvement could be reduced to a great extent, because the time-consuming liquid culture processes did not need to performed for the unfavorable mutants belonging to the groups other than group [A].

• KSBB Journal
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• v.9 no.1
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• pp.16-25
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• 1994

Sporulation mutants of Bacillus subtilis were developed for overproduction of heterologous proteins. The strains spoOJ spoIIG, and spoOJ spoIIG double mutant were constructed from two pretense-delfted mutant (DB104). The vector containing aprE gene was integrated in the chromosome of each strain, then the morphology of each strain was observed by TEM (trasmission electron microscopy). The morphology of spoOJ mutant and spoIIG mutant coincides with the description of the previous reports, respectively. The sporulating cells of spoOJ SpoIIG double mutation resemble spoIIG mutant more similarly, but with a little rougher cell wall membrane. The spoOJ mutation in B. subtilis gives negative effect on aprE activity with only a decreased sporulation frequency. On the contrary spoIIG mutation increases the aprE activity twice with an undetectable sporulation frequency. In the case of spoOJ and spolIG, i. e. double mutation, the effect of spoOJ on aprE activity seems to be relieved and the double mutant shows more or less the same aprE activity compared to spoIIG mutant.

• Korean journal of applied entomology
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• v.7
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• pp.57-59
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• 1969

Effect of light on conidial formation of Colletotrichum panacicola, C. gloeosporioides, C. runcatum and C. nicotianae was examined on potato dextrose agar on which each conidial suspension was seeded. The light source was Mitsubishi day light fluorescent lamps wi th an intensity of 100-120 ft-c at the colony surface. The treatments were (i)constant light, (ii) constant darkness, and (iii) alternating light (11hr.) and darkness {13hr.) at $26\{\circ}C\pm2$. With the exception of C. nicotianae, constant light gave the greatest sporulation over that obtained in the other two treatments; there were on significant differences in number of sporulation between under constant darkness and alternating light and darkness. C. nicotianae resulted in maximum. inter mediate and minimum sporulation under alternating light and darkness. constant darkness and constant light, respectively. These differences were statistically significant at $5\%$ level. C. truncatum and C. nicotianae produced abundant conidia in the entire test; C. gloeosporioides was intermediate, and C. panacicola was the least. Differences in number of sporulation due to light. organisms. and t he interaction of these two were all statistically significant.