Accumulation of Tetrahymena pyriformis on Interfaces

The behavior of ciliates has been studied for many years through environmental biology and the ethology of microorganisms, and recent hydrodynamic studies of microswimmers have greatly advanced our understanding of the behavioral dynamics at the single-cell level. However, the association between single-cell dynamics captured by microscopic observation and pattern dynamics obtained by macroscopic observation is not always obvious. Hence, to bridge the gap between the two, there is a need for experimental results on swarming dynamics at the mesoscopic scale. In this study, we investigated the spatial population dynamics of the ciliate, Tetrahymena pyriformis, based on quantitative data analysis. We combined the image processing of 3D micrographs and machine learning to obtain the positional data of individual cells of T. pyriformis and examined their statistical properties based on spatio-temporal data. According to the 3D spatial distribution of cells and their temporal evolution, cells accumulated both on the solid wall at the bottom surface and underneath the air–liquid interface at the top. Furthermore, we quantitatively clarified the difference in accumulation levels between the bulk and the interface by creating a simple behavioral model that incorporated quantitative accumulation coefficients in its solution. The accumulation coefficients can be compared under different conditions and between different species.

Nanosensors Based on Structural Memory Carbon Nanodots for Ag+ Fluorescence Determination

Ag+ pollution is of great harm to the human body and environmental biology. Therefore, there is an urgent need to develop inexpensive and accurate detection methods. Herein, lignin-derived structural memory carbon nanodots (CSM-dots) with outstanding fluorescence properties were fabricated via a green method. The mild preparation process allowed the CSM-dots to remain plentiful phenol, hydroxyl, and methoxy groups, which have a specific interaction with Ag+ through the reduction of silver ions. Further, the sulfur atoms doped on CSM-dots provided more active sites on their surface and the strong interaction with Ag nanoparticles. The CSM-dots can specifically bind Ag+, accompanied by a remarkable fluorescence quenching response. This “turn-off” fluorescence behavior was used for Ag+ determination in a linear range of 5–290 μM with the detection limit as low as 500 nM. Furthermore, findings showed that this sensing nano-platform was successfully used for Ag+ determination in real samples and intracellular imaging, showing great potential in biological and environmental monitoring applications.

Molecular Characterization of Gut Bacterial Flora of Honeybee (Apis Mellifera Adansonii) From Some Selected Apiaries in Ogun State, Nigeria

Research related to physiology and pathology of honey bees in particular Apis mellifera adansonii has attracted a lot of attention. The present study is aimed to determine honeybee (Apis mellifera adansonii) gut microbiome from Apiary in Olabisi Onabanjo University and Osoba Avenue Odo-Epo, Odogbolu Local Government. Twenty (20) honeybees workers (A. mellifera) were collected into a small vile containing sugar powder from the apiary located in OOU and Osoba Avenue at Odo-Epo during rainy season in July and transported to Zoology and Environmental Biology laboratory in OOU and kept in ice-cubes (-50C) till daybreak. Standard microbiological analysis for isolation of bacteria was used, adopting Clinical Laboratory Standard Institute procedures. The phylogenetic analyses based on the 16S rDNA gene were further used to characterize the organism in order to establish relationships among them. The results showed microbiota of the studied samples includes; Cedeca davisae, Cronobacter dublinensis, Enterobacter aerogenes, Kluyvera cryocrescens, Klebsiella oxytoca, Providencia vermicola, Salmonella enteric, Providencia alcalifaciens, Serratia nematodiphila, Pseudomonas plecoqlossicida, Klebsiella michiganensis, Serratia marcenscens, Pseudomonas aeruginosa, Escherichia coli, Aeromonas hydrophila and Enterobacter asburiae. Klebsiella spp. was more abundant and prominent in the digestive guts of honeybee workers both in OOU and Osoba Avenue, Odo Epo. The result of the percentage identity and closest accession of the isolates revealed that, Enterobacter aerogenes had the closest accession number and with highest percentage identity of (99%). The findings from this study showed that microbiota component communities of A. mellifera adansonii in OOU were composed of more Gram-negative bacteria than Gram-positive bacteria in Odo Epo.

Pre-service biology teacher’s perception on local environment problems as contextual learning resources

A survey and exploratory study were conducted to analyze Lake Tempe as a resource for contextual learning (CTL). The first phase of the study included exploring the lake’s potential through interviews with the people who live in the lake’s coastal region. Quadrat transects were done to identify aquatic plants around the lake. A feasibility analysis was conducted to see the lake’s potential as a learning resource. Field data were collected and compared to the environmental biology (EB) curriculum, responses, and learning outcome. The data were analyzed descriptively and tested using a paired-sample t-test. The results showed differences in the three stations’ physicochemical parameters and decreased quality of the water. It was found that anthropogenic activity had a significant contribution to the lake’s pollution. Nine species of six aquatic plant families were found in the lake. The survey revealed that the lake was feasible as a learning resource with criteria easy to access, safety, time efficiency, costs, and the material's suitability for EB courses. The t-test showed a difference in the students’ scores between before and after exploration practices. These findings suggest that Lake Tempe<em> </em>can serve as a resource for CTL in EB courses.

RGB Indices and Canopy Height Modelling for Mapping Tidal Marsh Biomass from a Small Unmanned Aerial System

Coastal tidal marshes are essential ecosystems for both economic and ecological reasons. They necessitate regular monitoring as the effects of climate change begin to be manifested in changes to marsh vegetation healthiness. Small unmanned aerial systems (sUAS) build upon previously established remote sensing techniques to monitor a variety of vegetation health metrics, including biomass, with improved flexibility and affordability of data acquisition. The goal of this study was to establish the use of RGB-based vegetation indices for mapping and monitoring tidal marsh vegetation (i.e., Spartina alterniflora) biomass. Flights over tidal marsh study sites were conducted using a multi-spectral camera on a quadcopter sUAS near vegetation peak growth. A number of RGB indices were extracted to build a non-linear biomass model. A canopy height model was developed using sUAS-derived digital surface models and LiDAR-derived digital terrain models to assess its contribution to the biomass model. Results found that the distance-based RGB indices outperformed the regular radio-based indices in coastal marshes. The best-performing biomass models used the triangular greenness index (TGI; R2 = 0.39) and excess green index (ExG; R2 = 0.376). The estimated biomass revealed high biomass predictions at the fertilized marsh plots in the Long-Term Research in Environmental Biology (LTREB) project at the study site. The sUAS-extracted canopy height was not statistically significant in biomass estimation but showed similar explanatory power to other studies. Due to the lack of biomass samples in the inner estuary, the proposed biomass model in low marsh does not perform as well as the high marsh that is close to shore and accessible for biomass sampling. Further research of low marsh is required to better understand the best conditions for S. alterniflora biomass estimation using sUAS as an on-demand, personal remote sensing tool.

Beneficial Insects Visiting Florals of Hamelia patens Rubiaceae (Jacq.) at a University Landscape in Nigeria

Aim: The study was carried out to ascertain how Hamelia patens would be valuable in sustaining diversity of beneficial insects. Study Design: Investigative cross-sectional study. Place and Duration of Study: The study was carried out at University of Port Harcourt, Nigeria. The insects and plants were processed for identification at the Laboratories of the Department of Animal and Environmental Biology and Plant Science and Biotechnology, University of Port Harcourt, Nigeria. Identification and curation of the insects was done at Insect Museum, Ahmadu Bello University Zaria, Nigeria. The study started in June and ended in September 2018. Methodology: The heights and canopy sizes of the Hamelia patens were measured with range pole and measuring tape. Insects associated with the floral parts of Hamelia patens were collected in the morning (08:00-10:00 am) and in the evening (4:00-06:00 pm) hours, with a sweep net. They were knockdown by pyrethrum insecticide and preserved in a bottle containing 70% ethanol. They were taxonomically grouped and sent to a taxonomist at Insect Museum, Nigeria for species identification. Results: Fifteen (15) insect species were collected on the Hamelia patens; Megachile mephistrophelica (Grib.), Megachile cinta (Fab.), Braunisca bilunta (Enderloein.), Pterandus sp., Lilioceris sp. and Virachola antalus (Hoph.) restricted their visitation on the plants only in the morning hours, Chelonus bifoveolatus (Szepg.) and Chrysolagria nairobana (Borch.) restricted their visitation in the evening hours. The remaining species were continuous on the plants. There was no significant difference (P=.05) between the number of insect species collected on taller plants and shorter ones. There was a significant difference between the insects that visited the plants in the morning and evening hours. Conclusion: The arrival of the insects on the Hamelia patens varied but some were time dependent. The clipping of the plant’s twigs affected the abundance of insects that visit the plant.

Effects of cowpea (Vigna unguiculata L. Walp.) as a Live mulch on weed management in maize cropping

Weed interference is a major constraint in maize cultivation. Living mulch as an alternative weed control strategy has been established to be environmentally safe but has not been widely used in maize cultivation. The aim of this research was to evaluate the weed management attributes of Vigna unguiculata in maize cropping. A field study was carried out in the crop garden of the Department of Crop Protection and Environmental Biology, University of Ibadan, Nigeria. The treatments were maize interplanted with Cowpea at 20,000 (M1), 30,000 (M2), 40,000 (M3) plants/hectare, hoe weeding (M4), weedy check (M5) and Primextra-2.5 L/ha (M6). The treatments were arranged in randomized complete block design, each replicated four times. Weed Dry Weight (WDW) and Weed Control Efficiency–WCE (%) were calculated following standardized methods. Data were analysed using descriptive statistics and ANOVA at α0.05. The treatment plots were dominated by weed species in the Asteraceae, Fabaceae and Poaceae families. The M5 accounted for the highest WDW (126.30 g). The WCE was highest in M3 (94.8%) and least in M5 (66.4%). Maize and cowpea interplant at 40,000 plants/hectare suppressed weed. Hence, cowpea is an ideal weed suppressant and can be inter-planted as a cover crop in maize cropping systems.

Predicting Ecosystem Metaphenome from Community Metagenome: A Grand Challenge for Environmental Biology

Elucidating how an organism’s characteristics emerge from its DNA sequence has been one of the great triumphs of biology. This triumph has cumulated in sophisticated computational models that successfully predict how an organism’s detailed phenotype emerges from its specific genotype. Inspired by that effort’s vision and empowered by its methodologies, this Viewpoint describes a grand challenge to predict the biotic characteristics of an ecosystem, its metaphenome, from nucleic acid sequences of all the species in its community, its metagenome. Meeting this challenge would integrate rapidly advancing abilities of environmental nucleic acids (eDNA and eRNA) to identify organisms, their ecological interactions, and their evolutionary relationships with advances in mechanistic models of complex ecosystems. Addressing the challenge aims to help integrate ecology and evolutionary biology into a more unified and successfully predictive science that can better help describe and manage ecosystems and the services they provide to humanity.

Environmental prevalence of toxigenic Vibrio cholerae O1 in Bangladesh coincides with V. cholerae non-O1 non-O139 genetic variants which overproduce autoinducer-2

Prevalence of toxigenic Vibrio cholerae O1 in aquatic reservoirs in Bangladesh apparently increases coinciding with the occurrence of seasonal cholera epidemics. In between epidemics, these bacteria persist in water mostly as dormant cells, known as viable but non-culturable cells (VBNC), or conditionally viable environmental cells (CVEC), that fail to grow in routine culture. CVEC resuscitate to active cells when enriched in culture medium supplemented with quorum sensing autoinducers CAI-1 or AI-2 which are signal molecules that regulate gene expression dependent on cell density. V. cholerae O1 mutant strains with inactivated cqsS gene encoding the CAI-1 receptor has been shown to overproduce AI-2 that enhance CVEC resuscitation in water samples. Since V. cholerae non-O1 non-O139 (non-cholera-vibrios) are abundant in aquatic ecosystems, we identified and characterized naturally occurring variant strains of V. cholerae non-O1 non-O139 which overproduce AI-2, and monitored their co-occurrence with V. cholerae O1 in water samples. The nucleotide sequence and predicted protein products of the cqsS gene carried by AI-2 overproducing variant strains showed divergence from that of typical V. cholerae O1 or non-O1 strains, and their culture supernatants enhanced resuscitation of CVEC in water samples. Furthermore, prevalence of V. cholerae O1 in the aquatic environment was found to coincide with an increase in AI-2 overproducing non-O1 non-O139 strains. These results suggest a possible role of non-cholera vibrios in the environmental biology of the cholera pathogen, in which non-O1 non-O139 variant strains overproducing AI-2 presumably contribute in resuscitation of the latent pathogen, leading to seasonal cholera epidemics. Importance. Toxigenic Vibrio cholerae which causes seasonal epidemics of cholera persists in aquatic reservoirs in endemic areas. The bacteria mostly exist in a dormant state during inter-epidemic periods, but periodically resuscitate to the active form. The resuscitation is enhanced by signal molecules called autoinducers (AIs). Toxigenic V. cholerae can be recovered from water samples that normally test negative for the organism in conventional culture, by supplementing the culture medium with exogenous AIs. V. cholerae belonging to the non-O1 non-O139 serogroups which do not cause cholera are also abundant in natural waters, and they are capable of producing AIs. In this study we characterized V. cholerae non-O1 non-O139 variant strains which overproduce an autoinducer called AI-2, and found that the abundance of the cholera pathogen in aquatic reservoirs correlates with an increase in the AI-2 overproducing strains. Our results suggest a probable role of these variant strains in the environmental biology and epidemiology of toxigenic V. cholerae, and may lead to novel means for surveillance, prevention and control of cholera.

Antioxidant Potentials of Blue Whiting Fish (Micromesistus poutassous) Oil Extracts in Streptozotocin Induced Diabetic Rats

Aim: The aim of this study was to assess the antioxidant potentials of Blue Whiting Fish (Micromesistus poutassous) oil extracts in streptozotocin induced diabetic rats. Study Design: An experimental study. Place and Duration of Study: Animal House, Department of Applied and Environmental Biology, Rivers State University, Port Harcourt and University of Port Harcourt Rivers State, Nigeria, between February 2020 and August 2020. Methodology: Thirty Six (36) albino rats were purchased and allowed to acclimatize for two (2) weeks in the laboratory at the animal farm house of the Department of Animal and Environmental Biology, Rivers State University. They were fed the normal rat feed (Chow feed) and water was allowed ad libitum. The rats were weighed and randomly grouped into six (6) groups with six rats in each group. Group 1 (Negative control) was placed on normal diet while groups 2 to 6 were placed on a high fat diet (HFD) prior to the induction with Streptozotocin to achieve diabetes and the animals were treated according to their groupings for four weeks by means of oral gavage. The dose of Blue Whiting Fish (Micromesistus poutassous) oil extracts administered to the rats was extrapolated from human doses. The high fat diet was prepared by mixing the animal feed (Chow diet) with margarine in a ratio of 3:1. After each period of treatments, blood samples were collected from the rats at the end of the treatments via cardiac puncture by anaesthetizing the rats with chloroform after a six (6) hour fast. Fasting blood glucose was determined using the Glucose Oxidase method, total antioxidant capacity, malondialdehyde, superoxide dismutase and glutathione were analysed quantitatively and measured spectrophotometrically and the GC–MS analysis of bioactive compounds from Blue Whiting Fish (Micromesistus poutassous) oil was done using Agilent Technologies GC systems with GC-7890A/MS-5975C model. Data generated were analysed using SPSS version 22.0 of windows statistical package. Results were considered statistically significant at 95% confidence interval (p < 0.05). Results: After week 1 - 4 of exposure, the mean SOD (Superoxide dismutase) value of the Negative control group (NC), Positive control (PC) group, diabetic groups exposed for weeks 1, 2, 3 and 4 expressed in U/ml were 299.41 ± 5.49, 217.38 ± 5.33, 220.56 ± 4.14, 240.45 ± 1.21, 258.19 ± 1.73 and 278.03 ± 1.98 respectively. The mean TAC (Total antioxidant capacity) value expressed in U/ml were 2.97 ± 0.10, 1.84 ± 0.04, 1.97 ± 0.04, 2.16 ± 0.02, 2.26 ± 0.02 and 2.46 ± 0.02 respectively. The mean GSH (Glutathione) expressed in µg/ml were 56.05 ± 0.60, 47.37 ±1.04, 47.94 ± 0.87, 50.80 ± 0.35, 53.07 ± 0.36 and 55.38 ± 0.33 respectively. The mean MDA (Malondialdehyde) expressed in nmol/l were 2.40 ± 0.13, 4.56 ± 0.28, 4.66 ± 0.06, 4.39 ± 0.01, 4.16 ± 0.03 and 3.70 ± 0.06 respectively. Comparison of different groups showed varying significant differences across groups. Conclusion: Hyperglycaemia induced in rats studied led to an increase in oxidative stress, depletion of antioxidant parameters was observed. However, after treatment with Blue Whiting Fish (Micromesistus poutassous) Oil extracts, it was observed that there was improvement in the overall antioxidant status of the rats.