Members of the genus Pleurotus, also commonly known as oyster mushroom, are well known for their socioeconomic and biotechnological potentials. Despite being one of the most important edible fungi, the scarce information about the genetic diversity of the species in natural populations has limited their sustainable utilization. A total of 71 isolates of Pleurotus species were collected from three natural populations: 25 isolates were obtained from Kakamega forest, 34 isolates from Arabuko Sokoke forest and 12 isolates from Mount Kenya forest. Amplified fragment length polymorphism (AFLP) was applied to thirteen isolates of locally grown Pleurotus species obtained from laboratory samples using five primer pair combinations. AFLP markers and internal transcribed spacer (ITS) sequences of the ribosomal DNA were used to estimate the genetic diversity and evaluate phylogenetic relationships, respectively, among and within populations. The five primer pair combinations generated 293 polymorphic loci across the 84 isolates. The mean genetic diversity among the populations was 0.25 with the population from Arabuko Sokoke having higher (0.27) diversity estimates compared to Mount Kenya population (0.24). Diversity between the isolates from the natural population (0.25) and commercial cultivars (0.24) did not differ significantly. However, diversity was greater within (89%; P > 0.001) populations than among populations. Homology search analysis against the GenBank database using 16 rDNA ITS sequences randomly selected from the two clades of AFLP dendrogram revealed three mushroom species: P. djamor, P. floridanus and P. sapidus; the three mushrooms form part of the diversity of Pleurotus species in Kenya. The broad diversity within the Kenyan Pleurotus species suggests the possibility of obtaining native strains suitable for commercial cultivation.

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Tylosema fassoglensis is a plant species that is native to Sub-Saharan Africa. The aim of this study was to evaluate the physicochemical properties of oil from T. fassoglensis in Kenya. Seeds of T. fassoglensis were collected from Mombasa, Taita Taveta, Homa Bay, and Siaya regions. Counts of T. fassoglensis in each region were recorded during the entire survey period. The highest distribution was recorded in Homa Bay followed by Siaya region. Distribution was the least in Taita Taveta and Mombasa regions. The analysis of the physicochemical characteristics of the oil was performed according to the official methods of analysis and the recommended practices of the American Oil Chemists Society. Oil content of 36.4% was obtained. The oil had refractive index 1.47 at 40°C, peroxide value 6.34 meq O2/kg, iodine value 94.06 g of I2/100 g, saponification value 145.93 mg KOH/g of oil, acid value 2.49 ± 0.56 mg KOH/g of oil, and unsaponifiable matter 5.87 g/kg. The oil had Lovibond color index of 2.0Y+28.0R. Oil content of T. fassoglensis is comparable with those of most oil crop under commercial production. The physicochemical properties of oil from T. fassoglensis are within the range recommended by FAO/WHO and hence suitable for human consumption.

In the present study, a fungal strain was isolated from mushroom waste dump-site and was described based on the morphological and molecular characteristics. The crude enzymatic extract was prepared by fermenting pineapple peels using the newly isolated fungal strain under solid-state condition. The enzymatic saccharification conditions of mushroom were optimized using the central composite design based on the response surface methodology. The isolate had black colony color, conidial head biseriate and small conidia which are synonymous with Aspergillus niger. The phylogenetic analysis using the rDNA ITS sequencing further revealed that the isolate was identical (≥99%) to A. niger. The crude extract displayed CMCase, Fpase and xylanase activities of 20.73U/mL, 34.57U/mL and 118.03U/mL respectively. The saccharification using the crude extract at optimal conditions of pH 6.5, temperature 50oC, enzyme loading of 5% (v/v) and time of 12h achieved maximum glucose yield of 1.639 mg mL-1 which is 1.1 folds higher than the predicted value. This study demonstrated the potential use of crude enzymatic extract from the newly isolated A. niger as a viable and efficient low-cost approach to mushroom processing using enzymes.