Weight Of Fruiting Bodies Research Articles

Use of various coffee industry residues for the cultivation of Pleurotus ostreatus in solid state fermentation

AbstractStudies were carried out to evaluate the feasibility of using coffee industry residues, viz. coffee husk, coffee leaves and spent coffee ground as substrates in solid state fermentation (SSF) to cultivate edible mushrooms Pleurotus. Eight strains of Pleurotus ostreatus and two strains of Pleurotus sajor‐caju were screened on a medium prepared from aqueous extract of coffee husk and agar. Based on best mycelial growth (9.68 mm/day) and biomass production (43.4 mg/plate in 9 days at 24°C), the strain P. ostreatus LPB 09 was selected for detailed studies. SSF was carried out using these substrates under different moisture conditions (45–75%) and spawn rates (2.5–25%). In general, although a 25% spawn rate appeared superior, the 10% spawn rate was recommended for all the three substrates in view of the process economics, as there was not any significant difference in the increase with 10 to 15%. The ideal moisture content for mycelial growth was 60–65% for coffee husk and spent coffee ground, and 60–70% for coffee leaves. The biological efficiency (BE), which is defined as the ratio of the weight of fresh fruiting bodies to the weight of dry substrate, multiplied by 100, and which indicates the fructification ability of the fungus for utilizing the substrate, was best with coffee husk. With coffee husk as the substrate, the first fructification occurred after 20 days of inoculation, and the biological efficiency reached about 97% after 60 days. When coffee leaves were used as the substrate, no fructification was observed even upon prolonged cultivation. With spent ground as the substrate, the first fructification occurred 23 days after inoculation and the biological efficiency reached about 90% in 50 days. There was a significant decrease in the caffeine and tannin contents (61 and 79%, respectively) of coffee husk after 60 days. It was remarkable to observe that caffeine was adsorbed onto the fruiting body (0.157%), indicating that it was not completely degraded by the fungal culture. However, no tannins were found in the fruiting body, indicating that the fungal strain was capable of degrading them. The results showed the feasibility of using coffee husk and spent coffee ground as substrates without any pre‐treatment for the cultivation of edible fungi in SSF, and provided one of the first steps towards an economical utilization of these otherwise unutilized or poorly utilized residues.

Cultivation characteristics of Isaria japonica

Cultivation characteristics of fruit-body (synnema) formation ofIsaria japonica were examined using liquid and solid media in order to produce fruit-bodies on a large scale. Mycelia grew well at 18–28°C on PDA medium with an initial pH of 7.0. The formation of fruit-bodies ofI. japonica was induced by lowering temperature to below 20°C in PD liquid medium. In sawdust-rice bran basal medium mixed with pupal powder prepared from silkworms (Bombyx mori), the fresh weight of fruit-bodies increased with increasing content of pupal powder. The highest yields of fruit-bodies were obtained in carbon-rich barley grain medium supplemented with pupal powder. The fruit-bodies grown under CO2 concentrations of 1,000 μl/L had coral-like, many-branched synnemata with numerous conidiospores, whereas those formed under high concentrations (9,000 μl/L) of CO2 had unbranched and longer synnemata. High concentrations of CO2 remarkably inhibited conidiospore formation on synnemata. Continuous high-intensity illumination at 2.93 W·m−2 inhibited the elongation of synnemata, and low-intensity illumination at 0.088 W·m−2 slightly inhibited the branching of synnemata. Fruit-bodies were produced on the pupa metamorphosed from living larvae ofAgrotis fucosa placed on the surface of a culture ofI. japonica incubated in sawdust-rice bran medium.

Protein and chitin nitrogen contents and protein content in Pleurotus ostreatus var. columbinus

Proteins and chitin were extracted and purified from dried fruitbodies of P. ostreatus var. columbinus grown on wheat straw and grass hay. Water- and sodium chloride-extractable proteins were purified by dialysis and precipitated by 10% TCA. These proteins contained 15.2% nitrogen (Kjeldahl and amino acid methods). The protein/nitrogen ratio of 6.58 was found and recommended as the new conversion factor. Chitin was purified from acid- and alkali-insoluble residue by 2% KMnO 4 and 15% NaHSO 3. This chitin contained 5.9% nitrogen and its infrared spectrum was similar to that of commercial chitins. The chitinous nitrogen content was about 0.34% dry weight of fruitbodies. The protein content was calculated from the non-chitinous nitrogen content and the factor 6.58. It was 17.1 and 23.5% dry weight of fruitbodies on wheat straw and grass hay, respectively, rather than 18.4 and 24.4% (as total nitrogen × 6.25).

Enzyme activities and substrate degradation during white rot fungi growth on sugar-cane straw in a solid state fermentation

Two strains of Pleurotus spp., grown in solid state fermentation on sugar-cane straw, degraded the dry matter by 50% after 60 days. The rate of substrate consumption and the dry weight of fruiting bodies decreased in consecutive flushings. Both strains vigorously attacked hemicellulose (80% of total degradation) and lignin (70%). Fruiting bodies were rich in protein and lipids, and had a low content of carbohydrates and ash.

Water relations of the mushroom culture Agaricus bisporus: Study of a single break

The relation between the decrease in moisture content of the casing soil and substrate and the increase of fruit body weight was investigated in cultures of a hybrid strain producing strong first breaks. During fruit body growth, the amount of water extracted from the casing soil was proportional to the weight of the fruit bodies on the culture. To keep the water content of the casing constant under growing conditions with low evaporation, the amount of water given to the casing from primordia formation up to any point in development had to be 44–54% of the weight of the fruit bodies of the culture at that time. The percentage of dry matter of fruit bodies decreased in both watered and unwatered cultures in the course of fruit body growth. Fruit bodies ready for harvesting from watered cultures had a significantly lower dry matter content than those from unwatered cultures. The water supply problems of mushroom cultures with very strong breaks are discussed.

Effect of 6-methyl-uracil and Ethrel on Various Strains of Agaricus bisporus (Lange, Singer)

Summary Various strains (D-13, F-1 and Pc-17) of champignon Agaricus bisporus (L ange , S inger ) were cultivated with the small scale method of plastic bags on compost supplemented by different amounts of two bioactive substances (6-methyluracil and Ethrel) respectively. The average yield of the mushroom (kg/q compost), the dry matter (in per cent of fresh weight), DNA-, RNA- (both: μ g/g fresh weight) and protein contents (mg/g fresh weight) of fruit bodies was evaluated. The experimental series indicated, that: the presence of 6-methyl-uracil and Ethrel in the compost induced a stimulation in the average yields of strains D-13 and F-1, but this promotion was smaller in the case of Pc-17. In correlation with the above described stimulation an increased level of DNA, RNA and protein contents was found. It was interesting, that the constant values of dry matter changed in a small interval only. The metabolic changes of various strains - with different morphological and physiological properties - seems to have a similar tendency (that is: an stimulated level of DNA, RNA and crude protein) with different intensity. These results showed that the effect of the applied compounds is similar to that observed in the higher plants.