Fungal contaminations of indoor and outdoor air of buildings of the University of Cape Coast,Ghana

The presence of microscopic spores in the air affects the quality of air inhaled by animals including humans.Microbial contamination of air impacts the well-being of occupants of an indoor environment,sometimes with dire consequences.The study investigated fungal contaminations of indoor and outdoor air of the Hospital,Library and Senior Common Room(SCR)of the University of Cape Coast,Ghana.Indoor and outdoor air was sampled using the Koch’s sedimentation method.Colony forming units per cubic meter of air(cfu/m^(3))were determined with the Omeliansky formula.The isolated fungi were identified based on morphological and growth characteristics.For indoor air,the least colony counts were recorded in the SCR for both morning and afternoon samples,whilst the Hospital air had the highest colony counts.For outdoor air,the colony counts were lower in SCR and the Library for both morning and afternoon samples compared to the Hospital.The results further indicated that indoor concentrations of fungi,for morning and afternoon,ranged between 4.0x10^(4) and 2.1x10^(5) cfu/m^(3),whereas outdoor concentrations of fungi ranged between 1.1x105 and 3.0x10^(5) cfu/m^(3),revealing an overall higher levels of contamination of outdoor air than indoor air at all the three buildings.Consequently,estimated indoor/outdoor(I/O)concentration ratios of fungi revealed an exogenous source of indoor contaminations at all the three buildings sampled.Fungi isolated from indoor and outdoor air were of the genera Aspergillus,Curvularia,Cylindrocarpon,Fusarium,Mucor,Neurospora,Penicillium and Rhodotorula.We conclude that indoor and outdoor air of the buildings sampled were contaminated with airborne fungi;however,based on estimated I/O ratios,the indoor ambient conditions of the buildings were good.The implication of findings of this study is that the presence of airborne fungal contaminants of indoor and outdoor workplace environment may pose serious occupational health consequences,hence low productivity.

Biotechnological potential of agro-industrial wastes for protein enrichment by solid-state fermentation using Aspergillus niger

This study is to assess the biotechnological potential of agro-industrial wastes of pineapple(Ananas comosus),sweet potato(Ipomoea batatas)and watermelon(Citrullus lanatus)for protein enrichment by solid-state fermentation using Aspergillus niger.Spore suspensions of A.niger were prepared with potato dextrose broth that had been supplemented with sodium chloride,ammonium nitrate and thiamine,and adjusted to pH of 5.Initial protein contents of sterile and non-sterile wastes of the pineapple,sweet potato,and watermelon were determined by the Kjeldahl method.The remaining sterile and non-sterile wastes was inoculated with spore suspensions of A.niger and incubated at temperature of 24℃ under conditions of solid-state fermentation for 14 days.Protein contents of the inoculated sterile and non-sterile wastes were determined after 7 and 14 days.The sterile wastes of pineapple,sweet potato and watermelon recorded initial percentage protein contents of 4.37,4.39,and 10.89,respectively,whereas their corresponding non-sterile wastes recorded initial percentage protein contents of 3.76,4.00,and 10.16,respectively.The results further show that percentage increase in protein content of sterile wastes after 14 days of fermentation were pineapple,35.01%;sweet potato,27.60%;and watermelon,64.40%.Percentage increase in protein content of non-sterile wastes after 14 days of fermentation were pineapple,72.34%;sweet potato,85.25%;and watermelon,80.51%.These findings affirm the biotechnological potential of pineapple,sweet potato and watermelon wastes and the importance of fungi as agents for protein enrichment of agro-industrial wastes.

The biotechnological potential of using mono-and co-cultures of Aspergillus niger van Tieghem and Trichoderma viride Pers ex Fr.to enhance the protein content of cassava(Manihot esculenta Crantz)peels by solid substrate fermentation

The application of fungal biotechnology for nutrient value addition and improvement of agro-industrial wastes is critical in the development of protein-rich feed for livestock.This study evaluated conventional methods for protein enrichment of cassava peels by solid substrate fermentation using mono-and co-cultures of Aspergillus niger and Trichoderma viride.Sterile and non-sterile cassava peels inoculated with mono-cultures of A.niger or T.viride and co-cultures of A.niger and T.viride were spontaneously fermented for 21 days at 24℃.Fermented substrates were harvested at 0,7,14,and 21 days intervals,then oven-dried at 60℃,milled in a blender and further assayed for ash,carbohydrate,crude fibre,fat,and protein contents.Results showed that percentage increase in protein contents after 21 days incubation of sterile cassava peels were 71.02%(for mono-culture of A.niger)and 71.64%(for mono-culture of T.viride);co-culture of A.niger and T.viride yielded a 129.00%increase in protein.Enhanced percentage increase in protein content of the non-sterile cassava peels was 126.80%(for mono-culture of A.niger)and 168.34%(for mono-culture of T.viride)in contrast with 63.47%obtained for the co-culture of A.niger and T.viride in non-sterile cassava peels,which was attributable to possible antibiosis due to microbial competition.Ash content significantly(p≤0.05)increased for 21 days while carbohydrate,crude fibre and fat contents in both sterile and non-sterile cassava peels decreased over the same period.These findings underscore the fact that protein content of cassava peels can be significantly(p≤0.05)enriched through fungal biotechnology to produce value-added feed supplement for livestock.The practical implications of these findings are discussed.

Protein enrichment of cassava pulp by solid-state fermentation using Aspergillus niger

This study aimed to assess protein enrichment of sterile and non-sterile cassava pulp using four strains of Aspergillus niger-AN1,AN2,AN3,AN4.First,studies were conducted to evaluate nutritional requirements of A.niger strains and their suitability for protein enrichment of cassava pulp.Second,sterile and non-sterile cassava pulps were inoculated with spores of A.niger strains and incubated under conditions of solid-state fermentation for 8 days using standard methods.Protein contents of sterile and non-sterile cassava pulps were determined by the Kjeldahl method.Initial nutritional requirements studies showed that A.niger strains grew at rates between 2.0 cm and 8.5 cm over 10 days on potato dextrose agar medium of different pH.The dry weight of mycelia of A.niger strains varied in liquid media separately supplemented with different concentrations of thiamine,ammonium nitrate and sodium chloride.A.niger strains also showed different levels of sporulation when cultured in growth media supplemented with different concentrations of sodium chloride.Increases in protein contents of sterile cassava pulp by AN1,AN2,AN3 and AN4 were 15.65%,22.61%,18.30%and 19.13%,respectively.On non-sterile cassava pulp,the increases in protein content by AN1,AN2,AN3 and AN4 were 15.40%,21.54%,10.80%and 3.85%,respectively.A.niger strain AN2 was the most suitable strain for the enrichment of protein content of cassava because it sparsely produced spores,it had the highest mycelial growth and resulted in the greatest increase in protein content of both sterile and non-sterile cassava pulp.