Journal of Environmental Microbiology and Toxicology

Control of Fungal Contaminants on Cocoa Pods Obtained from Akungba and Ogbagi Akoko

O.R. Adeoyo, E.F. Eweola — Mon, 23 Dec 2024 00:00:00 +0000

A cocoa pod has a thick, rough, and tough surface, which is usually filled with mucilaginous pulp that coats and protects cocoa beans. This mucilaginous pulp is sweet and allows growth of fungal contaminants. This study determined antifungal activity of some fungi obtained from some cocoa pods. Isolated organisms were cultured, identified using their macroscopic and microscopic characteristics, compared with those of compendium of soil fungi, pictorial atlas of soil, and seed fungi. Antifungal activity assay was conducted using agar-well diffusion method containing nystatin, fluconazole, ketoconazole or griseofulvin at 200 mg/mL, 100 mg/mL, and 50 mg/mL concentrations. The results revealed the presence of twelve fungal genera that include Aspergillus, Aureobasidium, Byssochlamys, Chrysosporium, Cladosporium, Colletotrichum, Curvularia, Epicoccum, Fusarium, Geomyces, Syncephalastrum, and Trichoderma. Aspergillus species had the highest percentage of occurrence (14.3%). The findings showed that all tested antifungal agents had varied degrees of inhibition against isolated organisms and that fluconazole had the highest inhibition zone of 40 mm against A. niger and S. racemosum (at a concentration of 200 mg/mL). Nystatin had the least antifungal activity against C. xerophilum (10 mm at 50 mg/mL) while griseofulvin had little or no activity against tested organisms. The findings underscore the need for proper monitoring to safeguard cocoa quality and to prevent likely cocoa beans spoilage via fungal contamination. The study recommends the use of nystatin, ketoconazole, and fluconazole for the control of fungal contaminants.

Bioremediation of Petroleum-Impacted Soil Using Poultry Manure

Anwuli U. Osadebe, Barisua Q. Nkoro — Mon, 23 Dec 2024 00:00:00 +0000

This 60-day study investigated the use of poultry manure (PM) at 10% w/w to drive crude oil elimination in impacted soil at a loading contaminant concentration of 5% v/w. Gas chromatography determined removal efficiency while the bacterial community was analysed using standard microbiological techniques. The presence of crude oil as a contaminant made the soil more alkaline and reduced its nutrient content across the board. The addition of PM improved soil nutrient properties and brought soil pH closer to neutral. PM amendment resulted in total petroleum hydrocarbon elimination levels of 96.83%. The total heterotrophic bacterial (THB) and hydrocarbon utilising bacterial (HUB) abundance in the PM-treated soils showed a steady rise till day 40 with values of 7.93 Log CFU/g and 8.83 Log CFU/g respectively, after which mean counts dropped. Statistically significant differences at 95% confidence interval (p≤0.05) in TPH elimination were seen between the control studies and the PM-treated soil. THB and HUB counts also differed significantly (p≤0.05) between the unpolluted control and the PM treatment study but no statistically significant differences were obtained between the PM-treated soil and the polluted control. Bacterial diversity analysis revealed a predominance of Bacillus spp., Staphylococcus spp., and Micrococcus on day 0. Dominance shifted to Klebsiella pneumoniae, Bacillus, and Citrobacter spp. by the end of the study, indicating that these genera were the drivers of crude oil biodegradation during the study. The application of poultry manure effectively enhanced the biodegradation of crude oil in impacted soil.

Clustering Analysis and Differentiation of Lard from Palm Oil and Soybean Oil Based on N-Alkane and Triacylglycerides Profiles Using Chemometric Analysis

Mon, 23 Dec 2024 00:00:00 +0000

This investigation focused on analyzing lard derived from pig adipose tissue and two different vegetable oils (crude palm oil and soybean oil) through triacylglycerides (TAGs) and n-alkane profiling, employing chemometrics techniques. Unsaponifiable palm and soybean oils were isolated and examined using gas chromatography-mass spectrometry (GC-MS) to assess their n-alkane profiles. The identified n-alkane profiles were verified by comparing them with n-alkane standards (nC08–nC27). The experimental design incorporated several multivariate techniques, including Hierarchical Clustering Analysis (HCA), Principal Component Analysis (PCA), Random Forest (RF), and Partial Least Squares-Discriminant Analysis (PLS-DA). According to PLS-DA findings, nC25, nC27, and PPL are suggested as key TAG and n-alkane markers for the clustering analysis of lard from crude palm and soybean oils. These results indicate that further research is necessary to refine and validate these distinctions, especially when using chemometrics techniques.

Liquid Tempeh Wastewater and EM4: A Combined Approach to Enhance Chilli Seed Germination

Mon, 23 Dec 2024 00:00:00 +0000

Tempeh liquid wastewater, a by-product of tempeh production, is increasingly recognized as a potential liquid fertilizer. However, research on its fermentation into fertilizer is limited. This study aimed to enhance tempeh wastewater-derived fertilizer using effective microorganisms 4 (EM4) and evaluate its impact on chili seed germination. Two sets of organic fertilizers were prepared, including three controls and three treatments. Controls were 100% distilled water, 10% EM4 with 90% distilled water, and 100% tempeh wastewater, while treatments varied in tempeh wastewater and EM4 concentrations. Chemical analysis revealed variations in total carbon, salinity, phosphorus, and potassium, with undetectable nitrogen content in all formulations. Formulations with 25% tempeh wastewater had lower salinity, phosphorus, and potassium than those with 75% tempeh wastewater. The effects on chili seed germination showed that formulation A3 (25% tempeh wastewater and 10% EM4) resulted in significantly higher germination percentage, mean daily germination, seedling length, and vigor index compared to controls and higher tempeh wastewater formulations. Overall, 25% tempeh wastewater formulations demonstrated superior germination and growth, suggesting tempeh liquid fertilizer as an eco-friendly and effective option for chili cultivation. Further research is needed to optimize its composition and application in agriculture.

Cytotoxic Effects of Cananga odorata Essential Oil on p53 Protein and TP53 Gene Dynamics in Non-Melanoma Skin Cancer

Wed, 25 Dec 2024 00:00:00 +0000

Skin cancer remains one of the most common cancers worldwide. Cananga odorata essential oil (CO EO) has shown potential anticancer and antioxidant properties, suggesting its application as a topical treatment for skin cancer. The objective of this study is to assess the cytotoxic effect of CO EO on non-melanoma skin cancer, TP53 gene expression, and p53 protein expression. The methodology involves HFF1 (human foreskin fibroblast) and A431 (human epidermoid squamous carcinoma) cell lines treatment with CO EO at 125, 250, and 500 μg/mL for 24 h. Morphological changes were observed under light microscopy. p53 protein expression and secretion were assessed using western blot. TP53 gene expression was quantified using real-time PCR. Our results show that CO EO treatment caused dose-dependent morphological changes in A431 cells, with increased non-viable cells observed. There was a 1.3-fold increase in p53 protein secretion in A431 cells treated at 250 μg/mL of CO EO. TP53 gene expression in A431 cells was significantly downregulated at 125 μg/mL (p = 0.03), while in HFF1 cells, TP53 was upregulated. To conclude, CO EO demonstrates cytotoxic effects on A431 cells, associated with altered p53 protein secretion and TP53 gene expression. Further studies are needed to elucidate its molecular mechanisms and therapeutic potential.

Characterization of Streptococcus agalactiae Strain TP540K and Its Potential as a Target for DNA Aptamer Development in the Preliminary Stage of Whole-Cell Based SELEX

Wed, 25 Dec 2024 00:00:00 +0000

Streptococcus outbreak caused mainly by Streptococcus agalactiae leads to massive mortalities of freshwater aquatic organisms, especially cultured tilapias. This has caused a huge concern in the Malaysian aquaculture industry due to a lower aquaculture production affected by the outbreak. Thus, there is a need for a rapid and simple method to detect and monitor S. agalactiae in cultured fishponds. This study aims to investigate the characteristics of a local S. agalactiae strain TP540K and its potential as a target bacterium to develop DNA aptamer through the whole-cell based ‘systematic evolution of ligands by exponential enrichment (SELEX)’ procedure. The morphology and biochemical characteristics of S. agalactiae strain TP540K were studied. Furthermore, the preliminary stage of the SELEX process was carried out by incubating S. agalactiae strain TP540K with a single-stranded DNA library. In this study, S. agalactiae strain TP540K was confirmed to be spherical, gram-positive, catalase and oxidase-negative with beta-haemolytic characteristics. Additionally, the presence of bands with an estimated size of 80-90 base pairs on the agarose gel indicated the presence of DNA aptamer that could bind towards S. agalactiae strain TP540K during the SELEX process. The findings herein demonstrate that S. agalactiae strain TP540K has the potential to be utilised as a target for the production of DNA aptamers, and subsequent rounds of whole-cell based SELEX process can be performed to investigate the binding affinity and specificity for more accurate detection of S. agalactiae in a future application.

Assessing Household Water Insecurity and Financial Capacity for the Cleaned Water Supply Services in Coastal Fishing Communities: A Case Study in Lok Dangkaan Village, Pitas, Sabah

Wed, 25 Dec 2024 00:00:00 +0000

Water security is a critical issue in rural coastal communities, and it has been proven to impact their health and socioeconomic productivity. Moreover, significant drought seasons may create prominent challenges for the communities. The objectives of this study are twofold: (1) to assess household water insecurity experiences and (2) to explore willingness to pay and ability to pay for better water supply for the Lok Dangkaan Village, Pitas district, a remote area with frequent drought climate in Sabah. A structured questionnaire was utilised in a cross-sectional survey of 45 households to gather information on demographics, socioeconomic status, and water-related concerns. The water insecurity was measured using the Household Water Insecurity Experiences Scale (HWISE). While the water consumption and affordability were measured by the ability to pay (ATP) and willingness to pay (WTP), with monthly water bills and water fee indicators respectively. Descriptive statistics and chi-square tests were used to analyze the data. The study found that most households engaged in fishing, have low incomes and limited access to basic amenities. Water quality is poor, though waterborne diseases are rare. Eighty-two percent of the households do not have access to clean water. The average estimated daily water consumption is 183.56 litres, with substantial variability. 75.6 percent of the households said they could afford to pay RM0.10 for every 1000 litres. On the other hand, their average monthly water bill during the dry season was RM121.67. The high level of water insecurity in Lok Dangkaan Village underscores the urgent need for improved water access and quality. While the forthcoming mini water treatment plant may address some issues, continued support and targeted interventions are necessary to enhance water security in the community.

Heavy Metal Pollution in Water and Sediment of Lohan River, Ranau, Sabah, Malaysia

Wed, 25 Dec 2024 00:00:00 +0000

Lohan River, a small stream near the former Mamut Copper Mine, receives sediment contributions from mine overburden and ultrabasic soils rich in Co, Cr, and Ni. This study investigated heavy metal enrichment in the riverbed sediments. Seven sampling stations were selected along the river, with additional control stations at Lohan Toki River and Moroli River. Heavy metals were extracted using the aqua regia method and analyzed via ICP-OES, with quality control including blanks and SRM digestions. Cr (218–700.68 mg/kg), Ni (238.47–679.22 mg/kg), and Cu (235.19–438.97 mg/kg) concentrations in Lohan River sediments exceeded high guideline values (H-GV) from the Australian and New Zealand Sediment Quality Guidelines (370 mg/kg for Cr, 52 mg/kg for Ni, and 270 mg/kg for Cu). Lohan Toki River sediments also showed Cr and Ni contamination, while Moroli River sediments remained below H-GV. Water samples recorded metal levels below Malaysia's Class IIA/IIB thresholds. Environmental indices classified Lohan River sediments as moderately to heavily polluted with Cr, Cu, and Ni (Igeo Class 3). Enrichment Factor (EF) values ranged from 4.94 to 11.67, indicating significant enrichment. Pollution Load Index (PLI) values showed localized moderate to heavy pollution at Stations 5 and 6. However, the values of Potential Ecological Risk Index (PERI) were below 150, indicating low ecological risk overall. Despite localized contamination, the water's heavy metal levels posed no immediate threat under current standards.