Improving the performance of mushroom in terms of high production and fast growth rate is essential in mushroom cultivation. In the present study the performance of Pleurotus ostreatus was evaluated using varying levels of wheat bran (WB) and maize flour (MF). The results indicated that Pleurotus ostreatus was highly influenced by different levels of supplementation, with 8% WB, 18% WB and 2% MF having higher contamination rate. The low levels of supplementation gave significantly better mycelial growth rate (MGR) and shorter colonisation period as observed that the control had highest MGR whereby 20% MF had lowest MGR. The pinning time (TP) was shortest at the first flush with minimum of 3 days (12% MF). The higher levels of supplementation showed maximum biological efficiency (BE) such as 14% MF, 12% WB and 14% WB. The yield was also higher at high levels of supplementation such as 20% MF and 8% MF being the exception in the lower levels. Based on the results it was observed that for fast production of oyster mushroom there is no need to supplement the maize stalk substrate but for improved productivity supplements can be added up to certain limits such as 14% MF and 12 WB. Keywords: biological efficiency; Pleurotus ostreatus; supplement; maize stalkPractical Application: The study will add to the pool of scientific knowledge relating to optimum substrate formulations (supplements) involving maize residues for Pleurotus ostreatus mushroom production. The results observed can be useful to small scale farmers who are willing to obtain good yield within minimal time at minimal cost with reduced contamination problems. Based on the results obtained, it is recommended that for fast production there is no need to add supplements on maize stalks but for improved production supplements can be added up to certain limits.

There is considerable national interest in the use of commercial microbially derived products for controlling the rate of accumulation of the contents of pit latrines. Manufacturers claim that some of these products can reduce accumulation rates, prevent the pit from ever filling up, or even result in decreases in pit contents volume. Prior to this research, there have been no scientific publications that have conclusively supported or refuted these claims. This project undertook to perform reproducible laboratory tests that would quantify the effect of commercial pit latrine additive products. Protocols were developed and tested on a range of different commercial products sold for their ability to control the rate of accumulation of pit latrine contents. The effect of commercial additives on mass loss from VIP sludge in 300 g honey jars was compared to mass loss from similar units subjected to no treatment and treatment with water. The purpose of these experiments was to separate and quantify the effect of microorganisms or enzymes originating from commercial pit latrine additives from the effect of natural processes within the pit latrine sludge (including digestion by microorganisms in the VIP sludge and dehydration) and the effects of other actions associated with treatment, such as the addition of water. Results indicated that insignificant mass loss occurred in all anaerobic test units, while significant mass loss occurred in all other test units. However, there was no statistically significant difference between any of the different treatments in the aerobic units. Investigation of analytical data from the test units indicated that mass loss in aerobic units was due to a combination of dehydration through evaporation of moisture and biological stabilisation processes, and that the latter were not significantly enhanced by the addition of commercial pit latrine products. It was concluded that there was no evidence to support claims that pit latrine additives could extend the life of a pit latrine.

The use of supplemented agricultural waste in mushroom cultivation can be one of the environmentally friendly strategies for poverty alleviation. The study evaluated the performance of Pleurotus pulmonarius mushroom grown on maize stalk supplemented with varying levels of wheat bran (WB) and maize flour (MF). A completely random design was used for the experiments. It was observed that Pleurotus pulmonarius was significantly affected by varying levels of supplementation, as 20% WB supplementation encountered higher contamination. The lower supplementation levels gave significantly shorter colonisation period with better mycelial growth rate (MGR). The 2% MF, 2% WB and 4% WB gave significantly higher MGR and faster colonisation. The shortest pinning time (TP) was observed at the first flush with the minimum of 2 days. Higher supplementation levels gave maximum yield and biological efficiency (BE). With further increase of supplementation above a 12% WB and 14% MF, the BE and yield declined. Lower supplementation levels resulted in quicker colonisation period and improved growth rate, whereas high supplementation gave better production in terms of yield and BE. Therefore, for the purpose of maximum production, 12% WB and 14% MF may be recommended while for fast production time, 2% MF and 2% WB are recommended.

Pleurotus ostreatus mushroom contains important bioactive compounds and has several biological activities; however, mushroom growing substrates have major influence on chemical and functional characteristics of the mushroom. Hence, the study aimed to evaluate the influence of supplementing mushroom growing substrates with wheat bran (WB) towards yield/productivity, bioactive compounds, and antimicrobial and antioxidant activity of P. ostreatus. The mushroom was cultivated on sugarcane substrates supplemented with increasing levels of WB (0%–20%). The mushroom extracts were screened for bioactive compounds using gas chromatography-mass spectrometry (GC-MS). Antimicrobial activity was carried out using microplate assay, while antioxidant potential was investigated using reducing power assay. The addition of supplements on mushroom growing substrates had an influence on mushroom yield; hence, higher supplementation (18% and 20%) produced higher yield. The GC-MS revealed several bioactive compounds with known activity, such as vitamin E, phenol, fatty acids, and terpenoids. Concentration-dependent antioxidant activity was observed; hence, extracts at higher concentrations gave significantly higher reducing power. The P. ostreatus extract had antimicrobial activity against all the tested organisms, with S. aureus showing high susceptibility to most of the extracts. However, mushrooms grown on bagasse substrates supplemented with 14% (0.02 mg/ml) and 20% WB (0.08 mg/ml) proved to have better antimicrobial activity on Escherichia coli. The difference in susceptibility demonstrates that substrates type and composition could have an influence on bioactive compounds found within mushrooms, also influencing medicinal properties of edible mushroom. Thus, supplementing mushroom growing substrates not only improve yield, but also can contribute to bioactive compounds with medicinal potential.

The sugar cane tops were obtained from farms around the northern part of KwaZulu-Natal province, South Africa (UVS farm at longitudes 28°42'24.9"S 31°54'09.0"E). The bagasse substrate, WB supplement and test mushrooms (P. ostreatus) were all obtained at the South African Department of Agriculture and Rural Development. The mushroom strain (P. ostreatus) was pre-cultured on potato dextrose agar and incubated in the dark environment at 25 ºC and then maintained as working spawn cultures at 4 ºC.The modified method outlined by Crisan and Sands (1978) was utilized for spawn preparation, whereby 1 kg of sorghum grains were soaked overnight in 1.5 l ABSTRACT Background: Pleurotus ostreatus, is one of the most cultivated mushrooms with great economic and medicinal value that can be easily grown on various bio-waste substrates. However, biosafety evaluations on these mushrooms are rarely conducted. Thus, we sought to evaluate the concentration or presence of Heavy metals in P. ostreatus mushrooms cultivated on agro-bio-waste products. Furthermore, the effect of adding agro wastes on wheat bran (WB) cultivated mushrooms was evaluated. Methods: Mushrooms grown in sugar cane tops and bagasse were supplemented with varying levels of WB. Atomic absorption spectrophotometer was applied to evaluate the concentration of heavy metals in the substrates and within mushrooms. Furthermore, DPPH free radical scavenging activity was used to determine antioxidant activity of mushroom extracts. Results: The transfer factor analysis (TF) showed that mushrooms have an affinity to absorb Zn, Cd, Cu and Cr from all tested substrates during cultivation (TF>1). The addition of WB supplement into substrates resulted into significant increase in mushroom yield. However, the increased addition of WB, inversely affected the DPPH scavenging activity of the P.ostreatus methanolic extracts. Conclusion: The bioabsorption of heavy metals by P. ostreatus is depended on the metal type. Based on these findings, mushrooms grown on these agro-waste appear to be safe and potent scavenging ability against free radicals.

This study aimed to biosynthesize zinc oxide nanoparticles (ZnO NPs) using Pleurotus ostreatus to achieve a simple ecofriendly method, and further evaluate antimicrobial activity and cytotoxicity towards HepG2 and Hek293 cells. The nanoparticles were characterized through UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission and scanning electron microscopy (TEM and SEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), and dynamic light scattering (DLS). The minimal inhibitory concentration (MIC) for antimicrobial activity and MTT assay for cytotoxicity were conducted in vitro. The study revealed an efficient, simple, and ecofriendly method for synthesis of ZnO NPs that have antimicrobial activity. UV-Vis showed peaks at 340 and 400 nm, and the bioactive compounds found in the mushroom acted as capping, reducing, and stabilizing agents. TEM characterized NPs as an amorphous nanosheet, with preferential orientation as projected by SAED patterns. The spherical and agglomerated morphology was observed on SEM, with EDX proving the presence of Zn and O, while XRD indicated a crystallite size of 7.50 nm and a stable nature (zeta potential of −23.3 mV). High cytotoxicity on Hek293 and HepG2 cells was noted for ZnO NPs. The study provides an alternative, ecofriendly method for biosynthesis of ZnO NPs that have antibacterial activity and potential use in cancer treatment.

In recent years, the potential of pathogenic bacteria to acquire resistance to a variety of antimicrobial drugs has developed significantly due to the indiscriminate exposure of a number of antibiotic compounds. The purpose of this study is to determine the antibacterial capabilities and activities of crude Pleurotus ostreatus extracts against Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Neisseria gonorrhoeae (ATCC 49926), and nine multidrug-resistant clinical isolates of Neisseria gonorrhoeae. All of these isolates exhibited sensitivity to azithromycin and ceftriaxone, while the majority of antibiotic resistance was seen against penicillin G, sulphonamide, and ciprofloxacin. Fifty percent of the isolates exhibited absolute resistance to both sulphonamide and ciprofloxacin, whereas 40% of the isolates displayed absolute resistance to penicillin G. The antibacterial activity of P. ostreatus extracts examined in this investigation varied within the same species of microorganisms. Extract B and D, extracted in the presence of 20% wheat bran bagasse and 20% maize flour bagasse, respectively, had exceptional antibacterial activity against all target isolates examined. We observed the lowest concentration of antibacterial agent required to inhibit the target bacteria to be between 1 × 10−3 mg/ml and 1 × 10−6 mg/ml with an estimated probability of 0.30769, a lower 95% confidence interval (CI) of 0.126807, an upper 95% CI of 0.576307, an estimated probability of 0.15385, a lower 95% CI of 0.043258, and an upper 95% CI, respectively. The MBC of 1 × 10−3 mg/ml was seen to eliminate 31% of the target bacteria. This dose was the most inhibitive. The antibacterial activity of all the extracts examined in the current study exhibited some degree of efficacy against both clinical isolates and standard strains. However, the majority of clinically isolated bacteria exhibited greater resistance to the extracts.

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