A total of 492 vegetable leaves samples made up of cabbage (27), bitter leaves (50), garden egg leaves (44), green leaves (66), green onion (47), lettuce (51), pumpkin leaves (111), parsley (26) and water leaves (70), bought randomly from various local markets in Port-Harcourt was analyzed for the presence of some parasite stages. About 145(29.5%) out 492 samples examined were contaminated with various parasite stages. Green leaves had the highest level of contamination (40.9%), followed by bitter leaves (38.8%), while cabbage recorded the lowest (7.4%). Out of 202 parasite stages identified, the eggs of Ascaris lumbricoides were the most predominant 39 (19.3%), followed by the cysts of Entarmoeba histolytica 31 (15.3%), whereas the oocysts Cryptosporidium parvum and eggs of Strongyloides stercolaris had the least 4 (1.9%). Green leaves and pumpkin leaves harboured 8 (80.0%) and 7 (70%) respectively out of 10 different types of parasites obtained in this study; cabbage and parsley had only 3 (30.0%).Pumpkin leaves recorded the highest level eggs of Ascaris lumbricoides 18(30%), eggs of Fasciola species 10 (16.7%), cysts of Entamaeba histolytica 8 (50.0%), eggs of Giardia lambia 7 (11.7%), whereas cabbage overall had the lowest percentage of parasites with Ancylostoma duodenale 2 (50.0%); eggs of Toxoplasma gondii 1 (25.0%) and eggs of Strongyloides stercolaris 1 (25.0%). The present study revealed the potential hazard of vegetable leaves sold in some local markets in Port -Harcourt. Though the vegetables are properly de-contaminated after sales at the point of preparation/cooking, it is also very necessary for the de-contamination to be done before sales. There is

ABSTRACT:The effect of disposing municipal waste on soil was evaluated by analyzing the microbiological and enzyme activity of soil samples at three different locations, from five municipal waste dumpsites and compared with soil samples from a farmland which serves as the control. Soil microbial load, physicochemical parameters and enzyme activities were determined using standard procedure. The highest heterotrophic bacterial count (1.02 ± 0. 4 × 10 7 cfu/g) was recorded from New Benin market Dumpsite (sampling point A) while the least (3.25 ± 0.4 ×10 4 cfu/g) was from the control (sampling point C). The result obtained showed that there was significant difference (p> 0.05) in the Heterotrophic bacteria and fungi count between the control and the soil samples from the various locations of the dumpsites. The bacteria identified were Acinetobacter species, Micrococcus luetus, Pseudomonas aeruginosa, Serratia species, Bacillus subtilis, Klebsiella species, Staphylococcus aureus, Arthrobacter species, Escherichia coli and Streptococcus feacalis, while fungi identified were Aspergillus niger, Trichoderma species, Penicillium species, Fusarium species, Mucor species, Saccharomyces species, Rhizopus species. Pseudomonas aeruginosa was the most prevalent bacterial isolate (20.3 %) while Streptococcus feacalis was the least isolate (3.1 %). Aspergillus niger was the most prevalent fungi isolate and Fusarium species the least isolated fungi. The enzymatic profile revealed that Oba market and Satana market had the highest Dehydrogenase and Urease activities with the values of 23.70 ± 16.32 mg/g/6h and 97.90 ± 14.93 mg/g/24h respectively. The physicochemical parameter measured in this study showed that the soil samples were acidic (5.60 ± 0.17 -6.23 ± 0.35) and sandy (72.20 ± 4.11 -90.60 ± 0.00 %). Trace amount of zinc (0.10 ± 0.00 -1.53 ± 1.02 mg/kg), lead (< 0.01 -1.23 ± 0.17 mg/kg) and copper (0.01 ± 0.00 -0.80 ± 0.10 mg/kg) was observed in both the control soil and the test samples. The result showed that although municipal waste dump is an unsustainable practice, it has a positive impact on the quality of the soil samples examined. © JASEM https://dx.doi.org/10.4314/jasem.v21i5.28

The utilization of food waste into products like single cell protein is an alternative solution to global protein shortage and to alleviate pollution problems. This investigation was carried out with food wastes such as orange, pineapple, banana, watermelon and cucumber waste as growth media for A. niger using standard techniques. Data obtained showed that Banana waste medium gave a higher yield of A. niger biomass and protein content than other waste investigated with values 2.29±0.02 and 0.57±0.01 g/L respectively. Biomass yield from Banana waste medium was statistically significant with the other food waste (p< 0.05). Among the various supplemented nitrogen sources in the Banana waste medium, ammonium nitrate (NH4NO3) gave the highest biomass and protein yield of 3.20±0.02 and 0.79± 0.04 g/L respectively. Thus, the study revealed that A. niger biomass can be produced from food waste and optimal yield can be enhanced by supplementing the medium with ammonium nitrate.

Formic acid is one of the major inhibitory compounds present in hydrolysates derived from lignocellulosic materials, the presence of which can significantly hamper the efficiency of converting available sugars into bioethanol. This study investigated the potential for screening formic acid tolerance in non-Saccharomyces cerevisiae yeast strains, which could be used for the development of advanced generation bioethanol processes. Spot plate and phenotypic microarray methods were used to screen the formic acid tolerance of 7 non-Saccharomyces cerevisiae yeasts. S. kudriavzeii IFO1802 and S. arboricolus 2.3319 displayed a higher formic acid tolerance when compared to other strains in the study. Strain S. arboricolus 2.3319 was selected for further investigation due to its genetic variability among the Saccharomyces species as related to Saccharomyces cerevisiae and availability of two sibling strains: S. arboricolus 2.3317 and 2.3318 in the lab. The tolerance of S. arboricolus strains (2.3317, 2.3318 and 2.3319) to formic acid was further investigated by lab-scale fermentation analysis, and compared with S. cerevisiae NCYC2592. S. arboricolus 2.3319 demonstrated improved formic acid tolerance and a similar bioethanol synthesis capacity to S. cerevisiae NCYC2592, while S. arboricolus 2.3317 and 2.3318 exhibited an overall inferior performance. Metabolite analysis indicated that S. arboricolus strain 2.3319 accumulated comparatively high concentrations of glycerol and glycogen, which may have contributed to its ability to tolerate high levels of formic acid.

Waste generation demands that measures must be put in place in order to avert their detrimental effect to the environment. Bioconversion of agricultural waste to useful products like enzyme is a welcome development. Amylase production by Aspergillus niger via submerged fermentation of fruit wastes such as pineapple, orange, banana, cucumber and watermelon was investigated. Biomass of A. niger, amylase produced and pH of the fermenting fruit waste media were determined using standard techniques during submerged fermentation. From the data obtained Banana waste medium produced the highest yield of A. niger amylase (259.00 ± 1.23 U/mL) compared to other waste media at 4 d of fermentation. Amylase yield from Banana waste medium was significantly higher compared with the other fruit wastes (p < 0.05). Among the various supplemented nitrogen sources in the Banana waste medium, ammonium nitrate gave the highest amylase yield of 881.00 ± 16.97 U/mL while the least (549.5 ± 20.51 U/mL) was from potassium nitrate medium. Thus, the study revealed that A. niger can be used for amylase production from fruit waste and optimal yield can be enhanced by supplementing the medium with ammonium nitrate.