Experimental Planning for Production of β-D-Glucan: Purification and Fluorescence Properties from Basidiomycete Strains

Fruit and coffee industries are responsible for huge quantities of agro-industrial wastes which is of great environmental and public health concern. Therefore, the aim of this work involves the use of such wastes for the production of β-D-glucan from basidiomycete strains which are powerful biological response modifiers in several clinical disorders. Experimental planning for optimization of several parameters was carried out by a full factorial of two levels of three factors for production of beta-glucans and basidiomycete species, where waste concentration and interaction between species and agro-industrial waste were the most important factors. The best conditions involved a basidiomycete strain of Lentinula edodes in a culture medium containing 400 g/L of waste coffee grounds which revealed the production of extracellular β-glucans (141.16 mg/L) at the 3rd day of fermentation. Intrinsic fluorescence properties of mushroom β-D-glucan were investigated by fluorescence spectroscopy as well as a fluorescence microtiter plate reader exhibiting emission peaks at 492 and 528 nm. Differential chromatographic behavior of β-D-glucan was investigated by immobilized metal affinity chromatography (IMAC) using epoxy-activated Sepharose 6B containing different chelating agents, spacer arms, and metal ions. One-step purification of β-D-glucan was devised using a column of epoxy-activated Sepharose 6B-IDA-Cu (II). FTIR analysis of several β-D-glucans from the chromatographic fractions was carried out to investigate their structural properties.