Design and parallelisation of a miniature photobioreactor platform for microalgal culture evaluation and optimisation

Miniature photobioreactors (mPBr) represent a potential platform technology for the high-throughput, phototrophic cultivation of microalgae. This work describes the development and characterisation of a novel orbitally shaken twin-well mPBr, and its scale-out to a 24-well microplate format, suitable for optimisation of microalgae culture conditions. Fluid hydrodynamics, oxygen mass transfer coefficient (kLa) and light intensity distribution in the mPBr were first investigated as a function of orbital shaking frequency. High speed video analysis of the shaken wells indicated rapid fluid flow and good mixing while measured kLa values varied between 20 and 80 h−1. Light intensity variation across the scaled-out platform was in the range ±20 μmol m−2 s−1. The use of the mPBr platform was demonstrated for optimisation of conditions for the batch cultivation of Chlorella sorokiniana. Using a modified tris-base phosphate (TBP) medium, the highest biomass concentration and productivity achieved were 9.2 g L−1 and 2.5 ± 0.2 g L−1 d−1 respectively at 5% CO2 with a light intensity of 380 μmol m−2 s−1. In general, cell growth rate and yield increased with increasing shaking frequency (up to 300 rpm) while culture conditions had limited impact on pigment production. Overall, these results demonstrate the application of the mPBr for rapid optimisation of phototrophic culture conditions and establishment of high cell density cultures

Engineering characterisation of a shaken, single-use photobioreactor for early stage microalgae cultivation using Chlorella sorokiniana.

This work describes the characterisation and culture performance of a novel, orbitally shaken, single-use photobioreactor (SUPBr) system for microalgae cultivation. The SUPBr mounted on an orbitally shaken platform was illuminated from below. Investigation of fluid hydrodynamics indicated a range of different flow regimes and the existence of 'in-phase' and 'out-of-phase' conditions. Quantification of the fluid mixing time (tm) indicated a decrease in tm values with increasing shaking frequency up to 90 rpm and then approximately constant tm values in the range 15-40 s. For batch cultivation of Chlorella sorokiniana, the highest biomass concentration achieved was 6.6 g L(-1) at light intensity of 180 μmol m2 s(-1). Doubling the total working volume resulted in 35-40% reduction in biomass yield while shaking frequency had little influence on culture kinetics and fatty methyl esters composition. Overall this work demonstrates the utility of the SUPBr for early stage development of algal cultivation processes

Genome-wide DNA methylation map of human neutrophils reveals widespread inter-individual epigenetic variation

The extent of variation in DNA methylation patterns in healthy individuals is not yet well documented. Identification of inter-individual epigenetic variation is important for understanding phenotypic variation and disease susceptibility. Using neutrophils from a cohort of healthy individuals, we generated base-resolution DNA methylation maps to document inter-individual epigenetic variation. We identified 12851 autosomal inter-individual variably methylated fragments (iVMFs). Gene promoters were the least variable, whereas gene body and upstream regions showed higher variation in DNA methylation. The iVMFs were relatively enriched in repetitive elements compared to non-iVMFs, and were associated with genome regulation and chromatin function elements. Further, variably methylated genes were disproportionately associated with regulation of transcription, responsive function and signal transduction pathways. Transcriptome analysis indicates that iVMF methylation at differentially expressed exons has a positive correlation and local effect on the inclusion of that exon in the mRNA transcript

Understanding How Microplastics Affect Marine Biota on the Cellular Level Is Important for Assessing Ecosystem Function: A Review

Plastic has become indispensable for human life. When plastic debris is discarded into waterways, these items can interact with organisms. Of particular concern are microscopic plastic particles (microplastics) which are subject to ingestion by several taxa. This review summarizes the results of cutting-edge research about the interactions between a range of aquatic species and microplastics, including effects on biota physiology and secondary ingestion. Uptake pathways via digestive or ventilatory systems are discussed, including (1) the physical penetration of microplastic particles into cellular structures, (2) leaching of chemical additives or adsorbed persistent organic pollutants (POPs), and (3) consequences of bacterial or viral microbiota contamination associated with microplastic ingestion. Following uptake, a number of individual-level effects have been observed, including reduction of feeding activities, reduced growth and reproduction through cellular modifications, and oxidative stress. Microplastic-associated effects on marine biota have become increasingly investigated with growing concerns regarding human health through trophic transfer. We argue that research on the cellular interactions with microplastics provide an understanding of their impact to the organisms’ fitness and, therefore, its ability to sustain their functional role in the ecosystem. The review summarizes information from 236 scientific publications. Of those, only 4.6% extrapolate their research of microplastic intake on individual species to the impact on ecosystem functioning. We emphasize the need for risk evaluation from organismal effects to an ecosystem level to effectively evaluate the effect of microplastic pollution on marine environments. Further studies are encouraged to investigate sublethal effects in the context of environmentally relevant microplastic pollution conditions

Semi‑continuous pilot‑scale microbial oil production with Metschnikowia pulcherrima on starch hydrolysate

Background: Heterotrophic microbial oils are potentially a more sustainable alternative to vegetable or fossil oils for food and fuel applications. However, as almost all work in the area is conducted on the laboratory scale, such studies carry limited industrial relevance and do not give a clear indication of what is required to produce an actual industrial process. Metschnikowia pulcherrima is a non-pathogenic industrially promising oleaginous yeast which exhibits numerous advantages for cost-effective lipid production, including a wide substrate uptake, antimicrobial activity and fermentation inhibitor tolerance. In this study, M. pulcherrima was fermented in stirred tank reactors of up to 350 L with 250-L working volume in both batch and semi-continuous operation to highlight the potential industrial relevance. Due to being food-grade, suitable for handling at scale and to demonstrate the oligosaccharide uptake capacity of M. pulcherrima, enzyme-hydrolysed starch in the form of glucose syrup was selected as fermentation feedstock.Results: In batch fermentations on the 2-L scale, a lipid concentration of 14.6 g L−1 and productivity of 0.11 g L−1 h−1 were achieved, which was confirmed at 50 L (15.8 g L−1; 0.10 g L−1 h−1). The maximum lipid production rate was 0.33 g L−1 h−1 (daily average), but the substrate uptake rate decreased with oligosaccharide chain length. To produce 1 kg of dry yeast biomass containing up to 43% (w/w) lipids, 5.2 kg of the glucose syrup was required, with a lipidyield of up to 0.21 g g−1 consumed saccharides. In semi-continuous operation, for the first time, an oleaginous yeast was cultured for over 2 months with a relatively stable lipid production rate (around 0.08 g L−1 h−1) and fatty acid profile (degree of fatty acid saturation around 27.6% w/w), and without contamination. On the 250-L scale, comparable results were observed, culminating in the generation of nearly 10 kg lipids with a lipid productivity of 0.10 g L−1 h−1.Conclusions: The results establish the importance of M. pulcherrima for industrial biotechnology and its suitability to commercially produce a food-grade oil. Further improvements in the productivity are required to make M. pulcherrima lipid production industrial reality, particularly when longer-chain saccharides are involved.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 665992

Effects of Ethanolic Extract of Hyptis Suavoelens on the Food, Water Consumption and Weight of Laboratory Experimental Rats

The need to identify medicinal plants that can be used in the treatment and control of malaria and other protozoal parasitic diseases is  underscored by the increasing resistance of Plasmodium(P.) species to hitherto widely used anti-malarial drugs such as chloroquine and more recently quinine. Resistance to these drugs which occurs with increasing frequency consequently underlies the necessity to develop  new agents for malaria chemotherapy, (family Labiatae) a plant traditionally used in the treatment of fever, as well as  related diseases and for repelling mosquitoes was screened for this purpose in the present study. The activities of the ethanolic extract of the leaves of this plant was  investigated against rodent , weight loss, feed and water consumption. A total of two hundred and fifteen animals, one hundred and fifteen Wistar rats and one hundred albino mice were used for the various aspect of the study. The LD50 of the extract was found to be 1264.91 + 0.51mg/kg (I.P) in mice and rats. Weight loss was observed in male and female rats to be significant (P < 0.05).Keywords :Ethanolic  leave  extract,  Plasmodium species,  family    Labiatae,  Hyptissuaveolens and malaria  chemotherapy

Production of bacterial amylase by Bacillus species isolated from rice husk dumpsites in Sokoto metropolis, Nigeria

Ten grams (10 g) of soil sample was obtained from a rice husk dumpsite in Sokoto metropolis and analyzed. The species isolated were Bacillus licheniformis, Bacillus lentus and Bacillus megaterium. The Bacillus species isolated were screened for amylolytic activities. The isolate with the widest zone of clearance (A1) was selected for further analysis. The highest activity was observed in B. licheniformis (2.00±0.01 mm) followed by B. lentus (1.96±0.40 mm) and B. megaterium (1.70±0.18 mm) had the least activity. Amylase activity was determined using DNS method. The optimum temperature for the activity of the amylase produced was obtained at 90 °C with a concentration of 0.373 mg/ml. Optimum pH activity was obtained at 4.0 with a concentration of 0.376 mg/ml. Bacillus licheniformis has the greatest potential for producing amylase than the other isolates and rice husk can be exploited for amylase production. The B. licheniformis strain producedthermostable alpha-amylase with characteristics suitable for application in starch processing and other food industries

Artificial Neural Networks, Optimization and Kinetic Modeling of Amoxicillin Degradation in Photo-Fenton Process Using Aluminum Pillared Montmorillonite-Supported Ferrioxalate Catalyst

An artificial neural network (ANN) was applied to study the hierarchy of significance of process variables affecting the degradation of amoxicillin (AMX) in a heterogeneous photo-Fenton process. Catalyst and H₂O₂ dosages were found to be the most significant variables followed by degradation time and concentration of AMX. The significant variables were optimized and the optimum condition to achieve degradation of 97.87% of 40 ppm AMX was 21.54% excess H₂O₂ dosage, 2.24 g of catalyst in 10 min. A mathematical model (MM) for the degradation of AMX was developed on the basis of the combined results of the ANN and the optimization studies. The MM result showed that increases in both catalyst and H₂O₂ dosage enhanced the rate of AMX degradation as shown by the rate constants evaluated from the model. The highest rate constant at the optimum conditions was 122 M^–1 S^–1. These results provided invaluable insights into the catalytic degradation of AMX in photo-Fenton process