• The Korean Journal of Mycology
• /
• v.25 no.1 s.80
• /
• pp.1-5
• /
• 1997

The cDNA encoding ${\beta}-tubulin$ of Pleurotus sajor-caju was isolated using an internal gene segment probe amplified by polymerase chain reaction (PCR) of genomic DNA and by cDNA library screening. The cDNA was consisted of 1560 nucleotides(nt), including a 5'-untranslation region (UTR) of 27nt, an open reading frame (ORF) of 1341nt, and a 3'-UTR of 191nt. The ORF encoded a protein of 446 amino acids(aa), which shows over 80% homology with ${\beta}-tubulins$ of other filamentous fungi. Southern hybridization analysis showed that there were two isotypes of ${\beta}-tubulin$ genes in P. sajor-caju. Through sequence analysis we found that ${\beta}-tubulin$ had a unusual $Cys^{165}$ residue, which might be a significant factor for the insensitivity of fungi to fungicide benomyl.

• The Korean Journal of Mycology
• /
• v.15 no.3
• /
• pp.135-141
• /
• 1987

Interspecific heterokaryons were obtained by polyethylene glycol induced fusion of protoplasts from auxotrophic mutants of P. ostreatus+P. cornucopiae, P. ostreatus+P. florida, P. ostreatus+P. sajor-caju, P. florida+P. cornucopiae, P. florida+P. sajor-caju and P. sajor-caju+P. cornucopiae protoplasts. The Fusion products of protoplasts were induced by MCM+benomyl, but segregation of sectors were not identified. Interspecific fusion products of protoplasts between incompatible strains did not form true clamp connections and did not produce fruit bodies. For induction of fertility, interspecific heterokaryons crossed with their parents by hyphal anastomosis.

• The Korean Journal of Mycology
• /
• v.13 no.1
• /
• pp.1-10
• /
• 1985

This experiment was undertaken to investigate proper conditions for protoplast isolation from strains of Agaricus bisporus, Flammulina velutipes, Lentinus edodes, Pleurotus florida, Pleurotus ostreatus, Pleurotus sajor-caju and Volvariella volvacea. Combination of ${\beta}-D-glucanase$, novozym 234 and snail enzyme with 0.6M $MgSO_4$ in 0.05M Na-maleate buffer, pH 5.8 was the most effective for isolation of protoplasts. High yields of protoplasts were obtained from $4{\sim}5$ days old mycelia of P. florida and P. ostreatus on mushroom complete agar medium. Protoplasts were also obtained in good yield from other fungi but A. bisporus and V. volvacea. In the latter two cases protoplast release was observed; however, the yield was much lower than those of the other fungi.

• The Korean Journal of Mycology
• /
• v.12 no.2
• /
• pp.59-64
• /
• 1984

The effects of cultural conditions in the rice straw media for cellulolytic enzymes production by Pleurotus sajor-caju were investigated. The optimum moisture content, pH and temperature for enzymes production were 60%, 7.0 and $35^{\circ}C$ in $C_1-cellulase$, and 60%, 5.0 and $25^{\circ}C$ in $C_x-cellulase$, and 60%, 7.0 and $20^{\circ}C$ in ${\beta}-glucosidase$, respectively. When light was irradiated during the cultivation period, $C_1-cellulase$ and ${\beta}-glucosidase$ production were decreased but $C_x-cellulase$ production increased at $500{\sim}1,000\;lux$. During the cultivation period, $C_1-cellulase$ production was contrary to $C_x-cellulase$ and ${\beta}-glucosidase$. Among the various materials added, rice bran was effective to $C_1-cellulase$ production, cotton seed cake and rice bran to $C_x-cellulase$ production, and defatted soybean and fish meal to ${\beta}-glucosidase$ production. The optimum concentration of rice bran for enzymes production were 20% in $C_{1-}$, $C_x-cellulase$ and 10% in ${\beta}-glucosidase$.

• The Korean Journal of Mycology
• /
• v.26 no.3 s.86
• /
• pp.354-360
• /
• 1998

We isolated three amplified DNA fragments from P. sajor-caju by Polmerase chain reaction (PCR) using the chithin synthase specific primers. Since the sequence analysis of the these fragments showed significant homology to the other known chitin synthase gene, we regarded these cloned fragments as PsCHS1, PsCHS2, and PsCHS3 according to their size. The PsCHS3, which showed the highest sequence homology (83% identity in amino acid level with ChsI of Rhizopus oligosporus in conserved region), was selected to see expression pattern of the corresponding gene. The result of RT-PCR using internal primer of the PsCHS3 fragment revealed that PsCHS3 gene was only expressed in cap and mycelium but not in stipe. In order to see whether the PsCHS3 gene was to be induced by wounding, the comparison of the mRNA level of this gene between wounded and unwounded mature cap showed at least two times induction of this gene by wounding treatment.

• Animal Bioscience
• /
• v.35 no.7
• /
• pp.999-1009
• /
• 2022

Objective: To improve the feeding value of rice straw (RS), this study evaluated the potential of rice straw fermented with Pleurotus sajor-caju (FRS) as dairy goat feed. Methods: Spent Pleurotus sajor-caju mushroom substrate was used as fungi inoculum to break the lignocellulose linkage of rice straw, which was solid-fermented at 25℃ to 30℃ for 8 weeks. The ruminal degradation of pangolagrass hay (PG), FRS, and RS were measured in situ for 96 hours in three dry Holstein cows, respectively. Effect of fungi fermented RS on milking performance was studied in feeding trials. A total of 21 Alpine goats a trial were divided into 3 groups: a control group in which PG accounted for 15% of the diet dry matter, and FRS or RS was used to replace the PG in the control group. Goats were fed twice a day under two 28-day trial in individual pens. Meanwhile, a 3×3 Latin square trial (14 days/period) was conducted to study the rumen digestion of three diets by using three fistulated dry goats. Rumen contents were collected for metabolite analyses every one to three hours on the last two days. Results: In situ study showed that fermentation could elevate the rumen degradable fraction and effective degradability of RS (p<0.05). Effective degradability of FRS dry matter was significantly increased from 29.5% of RS to 41.7%. Lactating trial results showed that dry matter intake and milk yield in the PG group and FRS group were similar and higher than those in RS group (p<0.05). The concentration of propionic acid and total volatile fatty acid in the RS group tended to be lower than those in PG group (p<0.10). There were no differences in rumen pH value and ammonia nitrogen level among the groups tested. Conclusion: Fermentation of rice straw by spent Pleurotus sajor-caju mushroom substrate could substantially enhance its feeding value to be equivalent to PG as an effective fiber source for dairy goat. The fermented rice straw is recommended to account for 15% in diet dry matter.

• The Korean Journal of Mycology
• /
• v.14 no.1
• /
• pp.37-41
• /
• 1986

The production of cellulolytic enzymes by Pleurotus sajor-caju JAFM 1017 was stimulated by folic acid and thiamine-HCl. Among the inorganic salts, optimum concentrations of $KH_2PO_4$ and $MgSO_4{\cdot}7H_2O$ were 0.2% (w/v) and 0.04% (w/v), respectively, but other inorganic salts were not effective for the production of the enzymes. The optimum culture temperature and pH for the production were $25^{\circ}C$ and 5.5 for avicelase, and $30^{\circ}C$ and 5.0 for CMCase, and $30^{\circ}C$ and 6.5 for ${\beta}-glucosidase$, respectively.

• Mycobiology
• /
• v.37 no.1
• /
• pp.37-42
• /
• 2009

Comparative effects of oyster mushrooms on plasma and fecal lipid profiles and on liver and kidney function were evaluated in hyper and normocholesterolemic rats. Feeding of hypercholesterolemic rats a 5% powder of oyster mushrooms (Pleurotus ostreatus, P. sajor-caju and P. florida) reduced the plasma total cholesterol level by 37%, 21% and 16%, respectively and reduced the triglyceride level by 45%, 24% and 14%, respectively. LDL/HDL ratio decreased by 64%, 45% and 41% for P. sajor-caju, P. ostreatus and P. florida fed rats, respectively. Mushroom feeding also reduced body weight in hypercholesterolemic rats. However, it had no adverse effect on plasma bilirubin, creatinin and urea nitrogen level. Mushroom feeding also increased the total lipid and cholesterol excretion in the feces. The present study reveals that feeding of 5% oyster mushroom powder does not have detrimental effects on the liver and kidneys rather may provide health benefits for the cardiovascular-related complication by decreasing the atherogenic lipid profiles.

• The Plant Pathology Journal
• /
• v.16 no.1
• /
• pp.25-28
• /
• 2000

The effect of ionic osmotic potential (Ψ$\pi$), and matric potential (Ψm) in the range of -0.2 to -4.0 Mpa on mycelial growth of three species of Pleurotus (P.florida, P.ostrenatus and P.safor-caju) were determined over a range of temperature (15-3$0^{\circ}C$) on a 2% malt extract agar medium and compared with the Ψ$\pi$ effect on growth of two strains of Trichoderma green mould. With the ionic solute KCl, optimun Ψ$\pi$for growth was -0.2 MPa for P.floreda and in the range of -0.2 to -0.5 MPa, with slight growth at -3.0 MPa and with nogrowth at -4.0 MPa. Of the species of Pleurotus, P.florida grew signigicantly slower than the other two species. Growt of the species of Pleurocus was significantly slower when water potential (Ψ$\omega$) was modified matrically with polyethylene glycol (PEG) 8000 then osmotically with KCl. They were also more sensitive to changes in Ψm than Ψ$\pi$The optimum Ψm of the Pleurotus was -0.5 Ψm, with no growth below -3.0 MPa. Of the species of Pleurotus, P.florida was most sensitive and P.sajor-caju was more tolerent to lowered Ψ$\pi$,but P.sajor-caju was most sensitive to lowered Ψm. The growth rate of the Trichoderma green mould strains was much faster than that observed for the Pleurotus spp. Optimum growth for bot strains of Trichoderma was in the range of -0.2 to -0.5 MPa. Strain CNU 503 was more tolerant to water stress than strain CNU 501. Both strains were able to grow up to 30% of optimum growth at -4.0 MPa at 25-3$0^{\circ}C$.

• The Korean Journal of Mycology
• /
• v.12 no.4
• /
• pp.133-140
• /
• 1984

Some properties of cellulolytic enzymes produced by Pleurotus sajor-caju JAFM 1017 during its growth in synthetic medium were investigated. The optimum pH of avicelase, CMCase, and ${\beta}-glucosidase$ was pH 5.5, pH 4.5 and pH 6.0, respectively. Avicelase and CMCase were stable within pH 5.0 to 6.0 and 4.0 to 6.0, respectively, and ,${\beta}-glucosidase$ was within pH 5.5 to 6.5. The optimum temperature of avicelase, CMCase and ${\beta}-glucosidase$ was the same of $40^{\circ}C$. The enzymes were stable below the optimum temperature, but the enzymes were unstable over the temperature of $50^{\circ}C$, and avicelase was losing about 91.7% of activity at $70^{\circ}C$ for 10 min. The enzyme activity of avicelase and CMCase was increased in proportion to the substrate concentration within 1% and 0.7%, respectively, and ${\beta}-glucosidase$ was within 0.1%. The Michaelis constants (Km) of avicelase and CMCase were 30.77mg avicel/ml and 14.64m Na-CMC/ml, respectively and ${\beta}-glucosidase$ was 5. 13mg salicin/ml. The reducing sugar production of avicelase was proportionaly increased until 120 min. and CMCase and ${\beta}-glucosidase$ were until 60min. The activity of three cellulolytic enzymes were increased by $Ca^{2+}$ at the concentration of $10^{-2}M$, but were inhibited by $Hg^{2+}$, $Ag^+$.