Aims: The study was carried out to isolate and identify the spontaneously growing populations of bacteria and fungi on the surface of biologically recovered polyhydroxyalkanoate (PHA) copolymer, poly(3-hydroxybutyrate-co-3- hydroxyhexanoate) [P(3HB-co-3HHx)]. Methodology and results: Large-scale PHA biosynthesis was carried out using 300 L fermenter and a biological methodology developed in our laboratory was utilized for PHA recovery. Using standard microbiological and molecular biology techniques the naturally growing microbial populations on the surface of biologically recovered PHA were identified. Scanning electron microscopy (SEM) analysis showed that the identified bacterial (Bacillus cereus and Burkholderia cepacia) and fungal isolates (Aspergillus niger, Byssochlamys nivea, Penicillium citrinum and Penicillium griseofulvum) were able to grow on and degrade the P(3HB-co-3HHx) copolymer. Conclusion, significance and impact of study: This is the first report on biologically recovered PHA pellet addressing the occurrence of microorganisms that grew spontaneously on it during storage under laboratory conditions. Fungi appeared to be dominant over bacteria in their ability to colonize the biologically recovered PHA.
Bacteria ; Fungi

Aims: The effect of different types of fungal inocula to the cellulase activity measured on palm kernel cake (PKC) was studied. Methodology and Results: Isolate Pro-A1 which was identified as Trichoderma sp. was selected as a potential producer of cellulase via solid state fermentation technique (SSF). Two types of PKCs were used; raw PKC (containing residual oil) and defatted PKC. The PKCs were inoculated with different concentrations of conidia and varying amounts (g) of solid mycelia plugs (SMP) for SSF. The effect of ultrafiltered crude fungal filtrate (CFF) as inocula was also being tested. The highest cellulase activity of 2.454 FPU/mL was detected with 60% (wt/wt) SMP applied to the raw PKC. Conversely, 2.059 FPU/mL of cellulase activity was measured when 80% (wt/wt) of SMP was applied to the defatted PKC which is 62.3% higher than the untreated defatted PKC; and more than 100% increase in enzymatic activity compared to raw PKC. The cellulase activity in the SSF inoculated with 8 x 106 conidia /mL and 12 x 106 conidia /mL were 1.704 FPU/mL for raw PKC and 1.856 FPU/mL for defatted PKC, an enhancement of about 46% from uninoculated batch. Inoculation with CFF bears corresponding maximum improvement of the cellulase activity on both PKCs of 13.58% (raw) and 2.86% (defatted). Conclusion, significance and impact of study: The current study proves that Trichoderma sp. in the form of SMP can enhance the cellulase activity on PKCs effectively with more than 100% increment. Fungal conidia are also a better choice in enhancing cellulase activity of Trichoderma sp. permitted that the PKC used is devoid of oil. From this study, Trichoderma sp. holds the potential of converting lignocellulosic materials into products of commercial and industrial values such as glucose and other biofuels.

Aims: The present study aimed to recognize the microstructure of conidiophores and spores of Penicilliumspp. which were isolated from clinical wastes. Methodology and results:The isolates of Penicilliumspp. were obtained from the solid clinical wastes on V8A medium and purified by single spore method. The culture characteristics were described in five culture media included; Czapek Yeast Extract Agar(CYA); Malt Extract Agar (MEA), Potato Dextrose Agar (PDA), Sabouraud Dextrose Agar (SDA) and Czapek-Dox Agar(CZ) while the conidiophores and spores were described using light and Scanning Electronic Microscope (SEM).Penicilliumspp. observedsome differences in their culture characteristics. Among 11 Penicilliumspecies isolated in this study and identified based on culture and microscope morphology. Five species including P. simplicissium,P. waksmanii,P. corylophilum andP. decumbensas well as one species identified as T. wortmanniiwere described in detailusing SEM. Conclusion, significance and impact of study:The study revealed that the microstructure of the fungal spores and conidiophores play an important role in the taxonomy of fungi species based on the phenotypic method.