PRODUCTION OF ALPHA AMYLASE AND CELLULASE FROM SOLID STATE CULTURE OF ASPERGILLUS OCHRACEUS: A FEASIBILITY ANALYSIS

The growing demand and application of industrially important enzyme necessitate the need to explore new sources with diverse enzymes ranging in their specificity and activities. Enzymes are safe alternatives to chemical synthesis due to minimum side effect and ease of manufacturing. Solid state fermentation (SSF) is a cost-effective alternative to submerged fermentation with agro-residues or waste, often being used as substrate for growing diverse organisms for production of metabolites. Current study is one of the scarce report on exploring alpha amylase and cellulase production ability Aspergillus ochraceus (MTCC 1877) using wheat bran as substrate at relative humidity of 90% and at 30 ºC, for 7 days. Result showed the potential of Aspergillus ochraceus (MTCC 1877), as potential source of the two enzymes. Results revealed comparatively higher alpha amylase activity in the SSF extract of Aspergillus ochraceus (MTCC 1877) in comparison to Trichoderma longibrachiatum (ITCC 7839). On the contrary, comparatively higher cellulase activity was observed in the SSF extract of Trichoderma longibrachiatum (ITCC 7839). The results showed the potential of Aspergillus ochraceus (MTCC 1877) as a source of the two enzymes. Variation in enzymes activity may be attributed to the experimental culture conditions and may be further optimized to enhance the enzymes yield.

OCCURRENCE OF AFLATOXIN M1 IN RAW ANIMAL MILK AND DAIRY PRODUCTS IN NORTHERN NIGERIA

A total of 144 samples of milk and milk products comprising 23 raw camel milk, 77 cow milk, 24 goat milk and 20 kindirmo (fermented milk) were randomly purchased across four states in northern Nigeria during July 2020 and screened for aflatoxin M1 (AFM1) using an Enzyme-linked immunosorbent assay method. The incidence (and mean values) of AFM1 in the camel milk, cow milk, goat milk and kindirmo samples were 74 % (38 ng/L), 99 % (92 ng/L), 100 % (112 ng/L) and 100 % (145 ng/L), respectively. The mean AFM1 levels in 22 %, 42 %, 83 % and 50 % of the camel milk, cow milk, goat milk and kindirmo samples, respectively, exceeded the European Union threshold of 50 ng/L. Results from this study suggest that consumption of raw animal milk and its products could be a contributing factor to aflatoxin exposure among households in northern Nigeria.

INCIDENCE OF MYCOTOXINS IN MOULDY SMOKED DRIED FISH AND MEAT (KUNDI) MARKETED IN SOUTHWESTERN NIGERIA

The mycotoxicological safety of 85 mouldy dried fish (n=40) and meat (n=45) samples purchased from Ijebu-ode, Ogun State and Aleshinloye, Ibadan, Oyo State markets both in South Western part of Nigeria respectively, was assessed due to heavy consumption of these animal protein sources by many low-income families in Nigeria. The presence of aflatoxigenic moulds and levels of aflatoxins in the samples were determined by the dilution plating technique and high performance thin-layer chromatographic method. The predominant fungal species isolated from the samples was Aspergillus niger-clade (49.65%); other species isolated include Aspergillus section Flavi (36.83%) and (13.52%). All samples analysed for mycotoxin presence were contaminated with aflatoxin B1. Aflatoxin B2, G1 and G2 were below detectable limits. About 13% of the samples had aflatoxin B1 concentration higher than the maximum acceptable level (10 ng/g). Results imply that the consumption of mouldy dried meat can result in serious public health hazard and hence there is need for advocacy programs to enlighten the populace on proper processing and storage of meat products.

ISOLATION AND MORPHOLOGICALLY IDENTIFICATION OF ASPERGILLUS FLAVUS INCIDENCES FROM MAIZE SEEDS IN ABUJA, NIGERIA

Food safety and security well implemented could help in making more crops available for consumption. Maize seed is a crop well known to be attacked by fungi such as Aspergillus flavus and reduce its nutrients. This study intends to isolate and morphologically identify the Aspergillus flavus from maize seeds from Abuja, Nigeria. The experimental design was complete randomized design involving untreated yellow (Y) and white (W) maize seeds from7 locations in Abuja, Nigeria. Pure culture of fungal isolate was prepared using Potato Dextrose Agar (PDA) and Sabouraud Dextrose Agar (SDA). Isolates obtained were characterized and identified on the basis of their colonial and morphological characteristics which include macroscopic and microscopic examinations. All maize seeds from the Abaji had no fungi incidences in both SDA and PDA, while all maize seeds from the experimental field show fungi incidences in both SDA and PDA. On SDA, the maize color yellow and white had F (2, 6) static values of 7.083 and 0.212 at p=0.129 and 0.941 respectively. For the PDA, white maize seeds and yellow maize seeds from all the locations had F (2, 6) static values of 0.377 and 0.521 at p=0.850 and 0.773. Aspergillus flavus was isolated in this study. The maize seeds from Kuje district and the experimental field 2 show a high incidence records. All growth of the Aspergillus in the two media used were not significant at p>0.05.

POTENTIAL IN BIOETHANOL PRODUCTION FROM VARIOUS AGRO WASTES FERMENTING BY MICROORGANISMS USING CARROT PEEL, ONION PEEL, POTATO PEEL AND SUGAR BEET PEEL AS SUBSTRATES.

Large amount of agro wastes are produced in Rwanda each year. The global annual potential bioethanol production from the major vegetables wastes such as carrot peel, onion peel, potato peel and sugar beet peel was estimated. Those wastes processing were successfully used as raw materials for the production of bioethanol, employing by cellulase produced from various filamentous fungi including Cladosporium cladosporioides was used for hydrolysis and the fermentation of the hydrolyzed samples was done using Sacharomyces cerevisiae. The fermented product was purified by primary distillation process at 79 °C and the fraction was collected. The ethanol is then determined by specific dichromate method and Gas Chromatography. Instantaneous saccharification and fermentation process yielded maximum ethanol in the substrate of carrot peel was 16.9 % at 21st day and further confirmed by Gas chromatography and the yield of ethanol obtained was 15.8 %.

ISOLATION OF AMYLASE PRODUCING FUNGI FROM CASSAVA FLOUR

Amylases are among the most important enzymes with potential applications in the present-day industry. Thus, isolating pure culture from cassava as the cheap source has manifold importance for food industries. In the present study, eleven amylase producing fungal strains were isolated from cassava flour and growth pattern, as well as optimum growth condition, was determined. All isolates showed amylases activity but isolate BR005, BR001 and GR003 recorded maximum clear zone diameters of 54.75 ± 0.957 mm, 53.25 ±0.645 mm 51.5 ± 1.414 mm, respectively. The submerged fermentation method was employed for crude amylase and biomass production. There were significant differences (p˂0.05) in starch concentrations and growth rates between the three isolates. GR003 and BR005 attained their optimal amylase activities of 4.23±0.25 U/mL and 3.75±3.16 U/mL at 50 °C, respectively, whiles BR001 attained its optimum amylase activity of 3.43±0.77 at 60 °C. Whereas, BR005, BR001 and GR003 attained their optimal amylase activity of 5.14±1.99 U/mL, 4.53±0.01 U/mL and 1.25±1.11 U/mL at a pH range of 6 to 7, making them neutrophilic fungi. Moreover, isolates BR005, BR001 and GR003 recorded the highest amylase activities of 4.31±0.14U/mL, 4.67±1.16±U/mL and 3.16±0.12U/mL at the starch concentrations of 3%, 2%, and 2.5% and fermentation period of 48 h, 66 h and 42 h, respectively. Lastly, BR005, BR001 and GR003 achieved their optimal amylase activities of 5.41±0.11U/mL, 6.24±0.14 U/mL and 6.22±0.12 U/mL at 48 h, 66 h and 42 h of incubation, accordingly. Indicating that cassava flour is a good source of amylolytic fungi with a potential application under wide conditions.

ANTIMICROBIAL EFFECTS OF SOME DICOTYLEDONOUS PLANTS ON FUNGAL ISOLATES OF CANDIDA albicans AND TRICHOPHYTON mentagrophyte

The preliminary phytochemical screening revealed that, antimicrobial properties of the leaf extracts were due to secondary metabolites such as amino acids, essential oils, flavonoids and saponins contained. The antimicrobial activities of alcoholic extracts were tested against pathogenic fungal isolates of Candida albicans and Trichophyton mentagrophyte. This was performed by inoculating the isolates into the pure extract, spread onto petri plates containing Sabouraud dextrose agar (SDA) media, observed for growth at stipulated standards. The sensitivity test was done by the disk diffusion method to test the effectiveness of an antimycotic (Griseofulvin) applied on the specific isolates. The minimum inhibitory concentration (MIC) was determined to ascertain the lowest drug concentrations that inhibited the fungal growths. The antimicrobial test revealed that, the leaf extracts of Eupatorium odoratum and Canjanus cajan inhibited the growths of the organisms while extracts of Citrus aurantifolia and Eucalyptus citriodora only prevented the growth of Candida albicans. The sensitivity test recorded the inhibition zone to range from 11 mm to 32 mm, with the lowest cleared area reported in the extract of E. citriodora and the highest in E, odoratum. Consequently, the MIC values of extracts at dilution levels were; E. odoratum: 1: 10000; 1: 1000, C. cajan: 1: 1000; 1: 10000, E. citriodora: 1:1000; 1:100 and C. aurantifolia: 1: 100000; 1: 100 respectively. This work has confirmed the progressive utilization of plants as antimicrobials for the benefit of mankind, to have originated from microbial sources.

YEAST DYNAMICS AND PHYSIOCHEMICAL EVALUATION OF CARROT WINE PRODUCED WITH Saccharomyces cerevisiae

Yeast dynamics and physiochemical evaluation of carrot wine produced with Saccharomyces cerevisiae were assessed. Fresh ripe and health carrot (6kg) were sequentially processed (washed, preheated, blended and sieved) into juice and fermented for 60 days with Saccharomyces cerevisiae. Airtight glass jars composed of juice (2000g), distilled water (2000mL) and sugar (200g) at controlled temperature (20 -25 0C) was used for fermentation. Wines were clarified (siphoning), aged (45 days) and pasteurized (500C – 600C) to stop fermentation. Proximate analysis, yeast dynamics, physiochemical and wine qualities were assessed. Result showed that juice extraction process reconstitute nutritional composition of carrot, such that moisture, ash and total carbohydrates increased, while others (fat, crude fiber and crude protein) decreased. A trendy progressive yeast dynamic model of Yeast load = -0.195 (Day) 2 + 1.822 (Day) + 4.566 with coefficient (R² = 0.907) was observed. Fermentation significantly decreased pH and increased total acidity. Observed wine qualities include alcoholic content (7.88 - 9.19%v/v), attenuation (121% - 142%) and calories (0%). Clarification and ageing have diminishing effect on alcohol content. Carrot wine was judged as physically appealing moderate alcoholic beverage, with smooth consistent taste (authors' opinion), and could be modeled with yeast dynamics. Thus this wine is recommended to calories sensitive people.

MICROBIOLOGICAL SURVEY AND DISSEMINATION OF FILAMENTOUS FUNGI OF PUBLIC HEALTH SIGNIFICANCE FROM WATER RESERVOIR (STORAGE TANK) IN CROWN ESTATE, IGBINEDION UNIVERSITY, OKADA, NIGERIA

Results of this investigation revealed that several species of filamentous fungi are present in the reservoir waters. Samples were collected from the surface and walls of the inner storage tank. The isolation process was done by a range of techniques and media, monitored by trained taxonomist to achieve broad arrays of water-borne fungi classified to species level. The direct plate enrichment counts and filtration technique recorded the highest number of counts (59 % and 32 %) respectively. The sabauraud dextrose Agar (SDA) was observed as the medium that recorded the highest colonies (60 cfu/100 ml) for incubation period of 5 d at 30 oC. Six different fungal taxa were recovered from the three examined sites (ST1, ST2 and ST3) and the ST3 was reported to have the highest number of isolated species. However, certain fungi were observed to be more distributed than others, specifically in species of Aspergillus and Penicillium which tended to be the most common. Although, species of other genera such as Acremonium sp., Rhizopus stolonifer, Mucor racemosus and Trichophyton sp. were also present but in low counts. The significance of fungi in water systems is lowly expressed as many of the species isolated from water sources are confirmed to possess the potentiality of secreting toxic secondary metabolites like patulin, produced by P. espansum causing immune-suppression in hosts, A.flavus secrets aflatoxins that can be carcinogenic, A. versicolour releases the musty odours in homes, while some moulds are concerned in food deterioration.

EFFECTS OF COMBINED INOCULATION OF BAMBARA GROUNDNUT (Vigna subterranean L. Verdc.) WITH GLOMUS MOSSEA AND BRADYHRHIZOBIUM JAPONICUM ON NITROGEN AND PHOSPHOROUS UPTAKE IN SHOOT, PLANT BIOMASS, LEAF CHLOROPHYLL AND MYCORRHIZAL INOCULATION EFFICIENCY (MIE).

The response of Bambara groundnut to co-inoculation with Abuscular mychorrhizal fungi (G. mossea) and Bradhyrhizobium japonicum (strain USDA110) with regard to leaf chlorophyll, percentage shoot nitrogen and phosphorus, nodule weight and plant biomass was studied. Bambara plants were grown under screen house conditions in pots. Plants were inoculated with 1ml of B. japonicum USDA 110 strain (109 cfu /ml), Mychorrizal was applied to the plants 10g, and 20g (90 spores/g) and water was applied at 10ml, 20 ml and 50ml every other day. The obtained results showed that dual inoculation activity was able to improve both nitrogen and phosphorus in plant shoot, MIE, but did not improve biomass and leaf chlorophyll when compared with plants subjected to single inoculation with only G. mossea and only B. japonicum. More Nitrogen and Phosphorus was retained in the shoot of plants co-inoculated with B. japonicum and 20g G. mossea when given 50ml of water and also had higher biomass. Leaf chlorophyll reduced in plants as flowering approached. B. japonicum was able to positively influence and establish symbiosis with G.mossea and synergistically effectively act as “mycorrhiza helper bacteria” (MHB) when both were co-inoculated in Bambara plant.