Agro-food waste employed to design and develop culture media for fungal growth

Aim: Waste from the agricultural and food industries could be used as a source of nutrients in the culture media for fungal growth and thus reduce environmental pollution and the cost of bioprocesses. In this work, it was determined if some agro-food waste can improve the mycelial growth of fungi and laccase production.Methodology: Culture media with agar and vermicompost, vermiwash, calcined pork bones or fish waste for mycelial growth of fungi were elaborated. The laccase activity of each strain grown in all culture media was also estimated. Results: Pleurotus eryngii, Lentinula edodes, Pleurotus ostreatus, Flammulina velutipes, Pleurotus citrinopileatus and Ganoderma lucidum grew in all culture media, except Lentinula edodes, obtaining in general higher biomass and radial growth rate than those observed on potato-dextrose agar. The maximum laccase activity was found in Pleurotus citrinopileatus cultivated in fish waste medium. The C: N ratio, ashes and pH were important factors for the growth of the strains. Interpretation: There were significant differences in biomass concentration and laccase activity in the designed culture media. These results provide an interesting alternative for the use of wastes and metabolites production of industrial interest.

Mycelial growth of strains of Pleurotus ostreatus developed on agar and its correlation with the productivity in pilot production farm

Radial growth rate, intracellular laccases and proteases activities, and protein content were evaluated in five strains of Pleurotus ostreatus, grown on starch-based and glucose-based agar media containing different concentrations of the glucose analogue 2-deoxyglucose (2-DG). Productivity of the strains in pilot scale cultivation was also determined. The mycelium of four strains had approximately between 0.6- to 3-fold higher protein content when grown on glucose medium containing 0.01 g/L of 2-DG than when grown on glucose medium. The radial growth rate and intracellular laccases activity of some strains showed a positive and a negative correlation with the productivity, respectively. These results suggest that the strains with high radial growth rate and low intracellular laccases activity on glucose without 2-DG, on starch without 2-DG or on glucose containing 0.01 g/L of 2-DG are highly productive in pilot production farm.

Avaliou-se o crescimento radial, as atividades de proteases e lacases e o conteúdo protéico de cinco cepas de Pleurotus ostreatus cultivado em agar à base de amido e à base de glicose contendo diferentes concentrações de 2-deoxiglicose (2-DG), um análogo da glicose. A produtividade das cepas em cultivo em escala piloto foi também determinada. Em quatro cepas o conteúdo protéico do micélio foi aproximadamente 0,6 a 3 vezes maior quando foram cultivadas em meio à base de glicose contendo 0,01g/L de 2-DG. O crescimento radial e a atividade de lacases apresentaram correlação positiva e negativa, respectivamente, com a produtividade. Esses resultados sugerem que as cepas com elevada taxa de crescimento radial e baixa atividade de lacases em glicose sem 2-DG, ou em amido sem 2-DG, ou em glicose com 0,01 g/L de 2-DG, são altamente produtivas em cultivo em escala piloto.