The Fatty Acid Methyl Ester (FAME) profile of Phytophthora agathidicida and its potential use as diagnostic tool.

Phytophthora diseases cause devastation to crops and native ecosystems worldwide. In New Zealand, Phytophthora agathidicida is threatening the survival of kauri, an endemic, culturally and ecologically important tree species. The current method for detecting P. agathidicida is a soil bating assay that is time-consuming and requires high levels of expertise to assess, thus limiting the analytical sample throughput. Here, we characterized the fatty acid methyl ester (FAME) profile of P. agathidicida. We also compared it with the FAME profile of P. cinnamomi and assessed the efficacy of FAME analysis as a diagnostic tool for detecting the pathogen in soil samples. In FAME analysis, the total fatty acid content is isolated from a sample and converted to FAMEs for analysis, a process that takes less than a day. Unique fatty acid acyl chains can serve as biomarkers for specific organisms. We detected 12 fatty acids in P. agathidicida, two of which (20:4ω6 and 20:5ω3) show promise as potential Phytophthora specific biomarkers. Collectively, these findings advance our fundamental understanding of P. agathidicida biology and provide a promising technique to increase the rate of sample processing and the speed of pathogen detection for P. agathidicida in soil.

Blended Sewage Sludge–Palm Kernel Expeller to Enhance the Palatability of Black Soldier Fly Larvae for Biodiesel Production

Black soldier fly larvae (BSFL) have been employed for valorizing organic waste materials as the larvae are able to consume organic waste and transform it into valuable larval biomass. In this study, BSFL were found to potentially reduce blended sewage sludge. The addition of palm kernel expeller (PKE) fortified the protein and lipid content in blended sewage sludge substrates, leading to larval growth enhancement. In addition, the larval weight also influenced the lipid yield and fatty acid methyl ester (FAME) profile. However, the optimum ratio of sewage sludge to PKE had to be determined as excess PKE content could become a threat to larval growth by contributing to the reduction of non-fiber carbohydrates content in the feed, thereby resulting in the decrease in lipid yield and FAME content. In this work, a sewage sludge to PKE ratio of 2:3 proffered the highest larval weight gained at 46.99 ± 2.09 mg/larva. Meanwhile, a proportion of 3:2 of sewage sludge to PKE was able provide the highest lipid yield of 17 ± 1.77%. Furthermore, the FAME profile revealed the presence of a significant amount of saturated and monosaturated fatty acids, indicating a good quality biodiesel. Thus, BSFL-based biodiesel fed with blended sewage sludge and PKE could be utilized for producing a high quality biodiesel. However, further improvement on the amount of lipid yield and FAME content should be further investigated.

First Report on Tertiary Amine as a Co2 Switchable Solvent for Hypersaline Trebouxiophycean Microalgae Towards Greener and Competent Lipid Extraction

Considering the momentous cost drivers in energy efficient algal biorefinery processes, a green alternative in the lipid extraction process from microalgae is anticipated. Switchable solvent system using tertiary amines namely DMBA (Dimethylbenzylamine), DMCHA (Dimethylcyclohexylamine), and DIPEA (Diisopropylethylamine) for lipid extraction from wet hypersaline microalgae was investigated in this study. Interestingly, showed that at 1:1 (v/v of fresh DMBA solvent: microalgal biomass), and for 1 h extraction time, the lipid yield was 41.9, 26.6, and 33.3% for Chlorella sp. NITT 05, Chlorella sp. NITT 02, and Picochlorum sp. NITT 04 respectively and for recovered DMBA solvent at 1:1 (v/v) and for 1 hour extraction time, the lipid yield was 40.8, 25.97, and 32%, respectively. Similarly, lipid extraction using DMCHA solvent for Chlorella sp. NITT 05, Chlorella sp. NITT 02, and Picochlorum sp. NITT 04 at 1:1 (v/v of solvent: microalgal biomass) and 1 h extraction time showed 34.28, 24.24 and 23.33% lipids, respectively for fresh solvent and 34.01, 24.24 and 23.18% for recovered solvent respectively; while DIPEA was not competent in lipid extraction from three tested microalgae. FAME profile shows the presence of major saturated fatty acid as C16:0 (~ 30%) and major unsaturated fatty acid as C18:1 (~17%).

Immobilised Chlorella vulgaris as An Alternative for The Enhancement of Microalgae Oil and Biodiesel Production

Microalgae are a promising alternative for biodiesel production and a valuable source of fatty acid methyl ester (FAME). In this research, Chlorella vulgaris has been chosen as the suitable microalgae because this species was able to produce highest oils for biodiesel processing. Previously, sodium alginate (SA) was used to entrap the microalgae in the culturing process due to its low toxicity and high transparency. However, SA have some disadvantages such as bead disruption which leading to the loss of microalgae cell. Therefore, this research has been conducted to evaluate the oil production of immobilised Chlorella vulgaris using different matric systems at different ratios which are 0.3:1, 1:1 and 2:1. Currently, six matric systems have been developed, they are SA as a control, a combination of SA and chitosan (SA+CT), SA and carrageenan (SA+CR), SA and gelatin (SA+GT), SA and calcium alginate (SA+CA), and SA and sodium carboxymethylcellulose (SA+CMC). The microalgae was first cultivated, harvested and extracted to produce oil, prior to use in the transesterification process. The SA+GT showed the highest oil yield with 59.14% and a total FAME of 0.56 mg/g. The FAME profile of oil extracted microalgae showed high potential for biodiesel production as it consisted of palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2) and linolenic acid (C18:3). The results proved that the combination of SA+GT had improved the oil yield and fatty acid composition as compared to the other matric systems, which may have useful application for the biodiesel industry. Copyright © 2020 BCREC Group. All rights reserved

Description and Genome Analysis of Methylotetracoccus aquaticus sp. nov. , a Novel Tropical Wetland Methanotroph, with the Amended Description of Methylotetracoccus gen. nov.

We enriched and isolated a novel gammproteobacterial methanotroph; strain FWC3, from tropical freshwater wetland, near Nagaon beach, Alibag, India. FWC3 is a coccoid, flesh pink/peach pigmented, non-motile methanotroph and the cells are present in pairs and as tetracocci. The culture can grow on methane (20%) as well as on a wide range of methanol from concentrations (0.02%-5%). Based on the comparison of genome data, FAME analysis, morphological characters and biochemical characters, FWC3 belongs to the tentatively and newly but not validly described genus ‘Methylotetracoccus’ of which only a single species strain was described, Methylotetracoccus oryzae C50C1. The ANI index between FWC3 and C50C1 strains is 94%, and the DDH value is 55.7%, less than the cut-off values 96% and 70%, respectively. The genome size of FWC3 is smaller (3.4 Mbp) compared to that of C50C1 (4.8 Mbp). Additionally, the FAME profile of FWC3 shows differences in cell wall fatty acid profiles compared to Methylotetracoccus oryzae C50C1. Also, there are other differences on the morphological, physiological and genomic levels. We propose FWC3 to be a member of a novel species of the genus Methylotetracoccus, for which the name Methylotetracoccus aquaticus is proposed. Also, an amended description of the genus Methylotetracoccus gen. nov. is given here. FWC3 is available in two international culture collections with the accession numbers: MCC 4198 (Microbial Culture collection, India) and JCM 33786 (Japan Collection of Microorganisms, Japan).

A Sugarcane-Bagasse-Based Adsorbent Employed for Mitigating Eutrophication Threats and Producing Biodiesel Simultaneously

Eutrophication is an inevitable phenomenon, and it has recently become an unabated threat. As a positive, the thriving microalgal biomass in eutrophic water is conventionally perceived to be loaded with myriad valuable biochemical compounds. Therefore, a sugarcane-bagasse-based adsorbent was proposed in this study to harvest the microalgal biomass for producing biodiesel. By activating the sugarcane-bagasse-based adsorbent with 1.5 M of H2SO4, a highest adsorption capacity of 108.9 ± 0.3 mg/g was attained. This was fundamentally due to the surface potential of the 1.5 M H2SO4 acid-modified sugarcane-bagasse-based adsorbent possessing the lowest surface positivity value as calculated from its point of zero charge. The adsorption capacity was then improved to 192.9 ± 0.1 mg/g by stepwise optimizing the adsorbent size to 6.7–8.0 mm, adsorption medium pH to 2–4, and adsorbent dosage to 0.4 g per 100 mL of adsorption medium. This resulted in 91.5% microalgae removal efficiency. Excellent-quality biodiesel was also obtained as reflected by the fatty acid methyl ester (FAME) profile, showing the dominant species of C16–C18 encompassing 71% of the overall FAMEs. The sustainability of harvesting microalgal biomass via an adsorption-enhanced flocculation processes was also evidenced by the potentiality to reuse the spent acid-modified adsorbent.