• 한국미생물·생명공학회지
• /
• 제27권6호
• /
• pp.466-470
• /
• 1999

Protease production and its characteristics were investigated with Mucor racemosus f. racemosus PDA 103 which was isolated from Korean traditional meju. Optimum culture conditions of the strain for the production of the protease in basic medium[bean(Baektae):H2O=1:1(w/v)] were as follows: pH 6, 3$0^{\circ}C$ and 72hrs. Optimum pH and temperature for the enzyme activity of the protease produced by Mucor racemosus f. racemosus were pH 5 and 5$0^{\circ}C$, respectively. The enzyme was relatively stable a pH2.0~5.0 and at temperature below 4$0^{\circ}C$. Phenylmethane-sulfonyl fluoride and Ag+ inhibited the enzyme activity. This indicates that the enzyme is serine protease. Km value was 0.9$\times$10-4M and Vmax value was 5.93$\mu\textrm{g}$/min. This enzyme hydrolyzed casein more rapidly than bovine albumin.

• 미생물학회지
• /
• 제29권5호
• /
• pp.284-289
• /
• 1991

the nucleotide sequence of the 3' terminal 568 bases of the 18S rRNA gene from Mucor racemosus was determined. The 3' end of the structural gene was identified by comparison with the published sequence for the Saccharomyces cerevisiae gene. The M. racemosus gene was found to share 83.8% homology with that of S. cerevisiae and 71-81% homology with those of human, mouse, maize, Xenopus laevis and Tetrahymena thermophila. The known methylation sites in X. laevis and human were also highly conserved in M. racemosus and located within most conserved regions of 18S RNA gene throughout evolution.

• 한국미생물·생명공학회지
• /
• 제27권6호
• /
• pp.446-451
• /
• 1999

The protease produced by Mucor racemosus f. racemosus PDA 103 from meju was purified by precipitating with 80% saturated ammonium sulfate, CM Sephadex C-50 ion-exchange chromatography, and secondary Sephadex G-100 gel filtration chromatography. The specific activity of the purified enzyme was 60.1unit/mg protein and the purification fold of the enzyme was 83.5. The molecular weight of the enzyme was estimated 33,746Da and the enzyme was elucidated as monomer by LC-MS and SDS-PAGE. The number of amino acids was evaluated about 330 residues.

• Mycobiology
• /
• 제33권4호
• /
• pp.240-242
• /
• 2005

A soft rot of fruits caused by Mucor racemosus occurred on cherry tomato collected in Agricultural Products Wholesale Market in Jinju, Korea. The disease infection usually occurred wounded areas after cracking of fruits. At first, the lesions started with water soaked and rapidly softened and diseased lesion gradually expanded. Colonies were white to brownish to gray in color. Sporangia were $32{\sim}54\;{\mu}m$ in size and globose in shape. Sporangiophores were $8{\sim}14\;{\mu}m$ in width. Sporangiospores were $5{\sim}12\;{\times}\;4{\sim}8\;{\mu}m$ in size, ellipsoidal to subglobose in shape. Columella was $27{\sim}42\;{\mu}m$ in size, obovoid, ellipsoidal, cylindrical-ellipsoidal, slightly pyriform in shape. Chlamydospores were numerous in sporangiophores and barrel-shaped when young, subglobose in old cultures. Optimum growth temperature was about $25^{\circ}C$. The fungus was identified as M. racemosus Fres.. This is the first report of soft rot on cherry tomato caused by M. racemosus in Korea.

• Journal of Microbiology and Biotechnology
• /
• 제20권2호
• /
• pp.332-339
• /
• 2010

The lipase from Mucor racemosus NRRL 3631 was partially purified by fractional precipitation using 60% ammonium sulfate, which resulted in a 8.33-fold purification. The partially purified lipase was then immobilized using different immobilization techniques: physical adsorption, ionic binding, and entrapment. Entrapment in a 4% agar proved to be the most suitable technique (82% yield), as the immobilized lipase was more stable at acidic and alkaline pHs than the free enzyme, plus 100% of the original activity was retained owing to the thermal stability of the immobilized enzyme after heat treatment for 60 min at $45^{\circ}C$. The calculated half-lives (472.5, 433.12, and 268.5 min at 50, 55, and $60^{\circ}C$, respectively) and the activation energy (9.85 kcal/mol) for the immobilized enzyme were higher than those for the free enzyme. Under the selected conditions, the immobilized enzyme had a higher $K_m$ (11.11 mM) and lower $V_{max}$ (105.26 U/mg protein) when compared with the free enzyme (8.33 mM and 125.0 U/mg protein, respectively). The operational stability of the biocatalyst was tested for both the hydrolysis of triglycerides and esterification of fatty acids with glycerol. After 4 cycles, the immobilized lipase retained approximately 50% and 80% of its original activity in the hydrolysis and esterification reactions, respectively.

• 한국식품과학회지
• /
• 제29권3호
• /
• pp.555-562
• /
• 1997

재래누룩 및 Mucor racemosus, Rhizopus japonicus, Aspergillus oryzae, Aspergillus kawachii균을 접종하여 만든 누룩으로 탁주를 담금한 후 발효과정 중의 품질을 검토한 결과는 다음과 같다. 에탄올함량은 담금직후 $2.0{\sim}3.0%$였으나 발효 16일에 $8.2%{\sim}12.6%$로 최대치를 나타냈다. Rhizopus japonicus, 재래누룩, Aspergillus kawachii, Aspergillus oryzae와 Mucor racemosus 누룩구의 술덧 순으로 높았다. pH는 담금 직후 pH $4.85{\sim}5.50$이였으나 발효 16일에는 pH $3.40{\sim}4.20$로 저하되었고 시험구 중 Rhizopus japonicus 누룩구의 술덧에서 pH가 높았다. 총산은 담금 직후 $0.15{\sim}0.20%$였으나 16일에 $0.86{\sim}1.57%$로 증가되었으며, 발효 16일에 Mucor racemosus 누룩구에서 1.57%로 시험구중 가장 높았다. 담금직후 총당의 함량은 $16.64{\sim}17.62%$, 환원당의 함량은 $4.62{\sim}5.63%$였으나, 발효 16일에 총당 $2.38{\sim}5.27%$, 환원당 $0.45{\sim}0.74%$로 감소하였고 Rhizopus japonicus구가 총당과 환원당 함량 모두 가장 낮았다. Ethanol을 제외한 알콜류 중 iso-amyl alcohol과 iso-butyl alcohol이 탁주술덧의 주성분이고, Rhizopus japonicus 누룩구에서 iso-amyl alcohol, iso-butyl alcohol, n-propyl alcohol의 함량이, Mucor racemosus 누룩구에서는 methanol의 함량이, 재래누룩구에서는 phenylethyl alcohol의 함량이 각각 높게 나타났다. 발효 중 생성된 퓨젤유는 $0.002{\sim}0.411\;mg/mL$ 이었다.

• 한국균학회지
• /
• 제21권3호
• /
• pp.172-187
• /
• 1993

전국 각지에서 수거한 메주로부터 29 종의 곰팡이를 분리하였다 . 그 중 접합균은 9 종이였다. 동정된 접합균으로는 M. hiemalis, M. circinelloides f. griseo-cyanus, M. circinelloides, M. jansseni M. racemosus f. racemosus, M. isabellina, R. stolonifer, R. oryzae, 및 A. corymbifera으로 4 속 9 종이었다. 분리된 접합균종 중에서M. circinelloides f. griseo-cyanus, R. stolonifer, R. oryzae은 이미 우리의 재래식 메주에 서식하는 균으로 간장, 된장 등의 장류분야에서 연구 보고도 되었으나, 나머지 6 종은 새로이 기재되는 균들이다. 분리된 9개의 균 각각으로 메주와 간장 된장을 만든 결과 접합균 중, M. hiemalis f. hiemalis. 와 M. circinelloides f. griseo-cyanus는 단독으로 메주가 되고, 우리 구미에 맞는 간장 된장이 되는 것을 관찰하였다. 따라서 이 균은 메주에서 어떤 역할을 하는 것으로 고려된다.

• Mycobiology
• /
• 제36권3호
• /
• pp.167-172
• /
• 2008

Beef luncheon meat is one of the most popular meals in several countries in the world including Egypt. Thirty one fungal species and 3 species varieties were recovered from 30 samples of beef luncheon meat collected from different supermarkets in Qena. Alternaria, Aspergillus, Emericella, Mucor, Mycosphaerella, Penicillium and Rhizopus were the most common genera on the two types of media. From the above genera, the most prevalent species were Alternaria alternate, Aspergillus flavus, A. fumigatus, A. niger, A. terreus, Emericella nidulans, Mucor racemosus, Mycosphaerella tassiana, Penicillium chrysogenum and Rhizopus stolonifer. Screening of fungi for their abilities to produce lipase enzyme showed that, ten isolates represented 32.26% of total isolates appeared high lipase production, while sixteen isolates (51.61%) were moderate and 5 isolates (16.13%) were low producers. Aspergillus niger, Fusarium oxysporum and Nectria haematococca produced the highest amount of lipase enzyme, so these fungi were used in further studies. The incorporation of five food preservatives (Disodium phosphate, sodium benzoate, citric acid, potassium sorbate and sodium citrate) individually in the culture medium of lipase production exhibited an inhibitive effect on the mycelial growth and enzyme production by Aspergillus niger, Fusarium oxysporum and Nectria haematococca.

• 한국생태학회:학술대회논문집
• /
• 한국생태학회 2002년도 VIII 세계생태학대회
• /
• pp.93-100
• /
• 2002

Dynamics of certain $N_2$fixing bacteria such as Rhizobium, Azospirillum and Azotobactor, nodule number in dominant legume, Atylosia trinervia, P-solubilizing bacteria, actinomycetes and fungi were studied in unburned and burned site of natural grassland, southern India. Population of $N_2$- fixing bacteria, P-solubilizing bacteria, fungi and nodule number in legume increased significantly in burned sites. On the other hand, the actinomycetes population remained unchanged. Thirty six species of fungi with tricalcium phosphate solubilizing ability were recorded. The most efficient P-solubilizing fungi recognised in the soils of the study sites are Absidia ramosa, Gongronella butlerii, Mortieralla spinosa, Mucor racemosus, Rhizopus nigricans, R. stolonifer, R. oryzae, Aspergillus fumigatus, A. nidulans, A. niger Theilavia terricola and Cheatomium lunasporium.

• 한국식품영양과학회지
• /
• 제26권5호
• /
• pp.759-766
• /
• 1997

From Nuruks, a traditional Korean starter for rice wine, collected from 42 different areas in Korea, 111 fungal strains were isolated. These isolates were identified as 25 species belonging to seven genera of Rhizopus oryzae(14 strains), R. oligosporus(8 strains), R. nigricans(5 strains), R. arrhizus (5 strains), Aspergillus oryzae(12 strains),Asp. parasiticus(8 strains), Asp. fumigatus(3 strains), Asp. ochraceus(7 strains), Asp. wentii(5 strains), Asp. parasiticus(8 strains), Asp. penicilloides(3 strains), Asp. clavatus(4 strains), Penicillium purpurogenum(2 strains), Pen. glabrum(1 strain), Pen. granulaturm (1 strsin), Pen. fellutanum(1 strain), Geotrichum candidum(2 strains), Absidia corymbifera(12 strains), Mucor racemosus(2 strains), M. plumbeus(2 strains) and Curvularia lunatus(3 strains).