Strains Of Algae Research Articles

Genome characterization of Shewanella algae in Hainan Province, China.

Shewanella algae is an emerging marine zoonotic pathogen. In this study, we first reported the Shewanella algae infections in patients and animals in Hainan Province, China. Currently, there is still relatively little known about the whole-genome characteristics of Shewanella algae in most tropical regions, including in southern China. Here, we sequenced the 62 Shewanella algae strains isolated from Hainan Province and combined with the whole genomes sequences of 144 Shewanella algae genomes from public databases to analyze genomic features. Phylogenetic analysis revealed that Shewanella algae is widely distributed in the marine environments of both temperate and tropical countries, exhibiting close phylogenetic relationships with genomes isolated from patients, animals, and plants. Thereby confirming that exposure to marine environments is a risk factor for Shewanella algae infections. Average nucleotide identity analysis indicated that the clonally identical genomes could be isolated from patients with different sample types at different times. Pan-genome analysis identified a total of 21,909 genes, including 1,563 core genes, 8,292 strain-specific genes, and 12,054 accessory genes. Multiple putative virulence-associated genes were identified, encompassing 14 categories and 16 subcategories, with 171 distinct virulence factors. Three different plasmid replicon types were detected in 33 genomes. Eleven classes of antibiotic resistance genes and 352 integrons were identified. Antimicrobial susceptibility testing revealed a high resistance rate to imipenem and colistin among the strains studied, with 5 strains exhibiting multidrug resistance. However, they were all sensitive to amikacin, minocycline, and tigecycline. Our findings clarify the genomic characteristics and population structure of Shewanella algae in Hainan Province. The results offer insights into the genetic basis of pathogenicity in Shewanella algae and enhance our understanding of its global phylogeography.

A self-isolated acid-tolerant Parachlorella kessleri with high efficiency in treating rare earth mining sewage

Rare earth mining sewage is a significant environmental concern due to its high acidity and ammonia nitrogen levels. Finding a sustainable and cost-effective treatment method is essential. Parachlorella kessleri FM2, a green algae strain isolated in-house, has demonstrated remarkable abilities to grow and remove ammonia nitrogen (NH4+-N) from highly acidic rare earth wastewater without the need for alkaline additives. After optimizing conditions, P. kessleri FM2 achieved an impressive NH4+-N removal rate of 7.94 mg/L/d and a removal efficiency of 98.71% in a 1.5-L photobioreactor. In semi-continuous culture, the average NH4+-N removal rate remained high at 6.67 mg/L/d. When scaled up to continuous culture in a 5-L photobioreactor, P. kessleri FM2 maintained stability with an NH4+-N removal rate of 6.79 mg/L/d. Additionally, we conducted a preliminary analysis of P. kessleri FM2's acid resistance mechanism, further highlighting its potential as a candidate for treating acidic wastewater.

Enhancing methane yield from microalgae: abiotic stress and cells disruption with quartz powder

This study investigates the biochemical methane potential (BMP) of microalgal biomass, introducing a novel cells disruption method using quartz powder (SiO2). A two-phase algae cultivation, involving nitrogen deprivation and salinity shifts, was employed to biochemically modify the biomass of two brackish green algae strains, Chlorella vulgaris and Monoraphidium contortum, enhancing their methane (CH4) production potential. Mechanical disruption of the algal cells further increased BMP, with C. vulgaris yielding 305 mL CH4/g volatile solids (VS) and M. contortum reaching 324 mL CH4/g VS, reflecting respective increases of 51 % and 86 %. The integration of this efficient mechanical cell disruption method with a simple, stress-based cultivation strategy presents significant potential for enhancing the methane yield of microalgal biomass.

Production of Bio-Diesel from Dairy Waste Scum

Abstract-Dairy factory waste scums are increasingly being considered a valuable resource. However, these wastes may also contain contaminants, natural or artificial, that may adversely affect the land or water to which they are discharged. The study investigates the potential of using dairy waste scum as a feed stock for bio-diesel production. Present study optimized the parameters involved in the alkali catalysed Trans esterification process of dairy waste scum oil. The effects of methanol to oil ratio, temperature and amount of KOH were investigated. A study was conducted to evaluate the capability of production of biodiesel from consortium of native microalgae culture in dairy farm treated waste water. Native algal strains were isolated from dairy farm waste waters collection tank (untreated wastewater) as well as from holding tank (treated wastewater). The consortium members were selected on the basis of fluorescence response after treating with Nile red reagent. Preliminary studies of two commercial and consortium often native strains of algae showed good growth in waste waters. A consortium of native strains was found capable to remove more than 98% nutrients from treated waste water. The biomass production and lipid content of consortium cultivated in treated waste water were 153.54t ha-1 year-1 and 16.89%, respectively. 72.70% of algal lipid obtained from consortium could be converted into biodiesel. The present study found that bio- diesel from dairy waste scum is quite suitable as an alternative to petroleum diesel with recommended fuel properties as per ASTM standards. By using dairy waste scum as a feed stock for bio diesel and the environmental impact related to the disposal of dairy scum Keywords: Environment,Bio-Diesel,Dairy Waste Scum, Extraction of Lipids

Effects of Non-steroidal Anti-inflammatory Drugs (Ibuprofen and Diclofenac) and Their Mixtures on the Growth of Three Green Algae

Ibuprofen (IBU) and diclofenac (DFN) are the most widely consumed non-steroidal anti-inflammatory (NSAIDs) worldwide. Since they are not completely metabolized in the human body, the unaltered active ingredients can reach aquatic ecosystems through domestic effluents. The aim of this study was to analyse the toxic effects of IBU and DFN, individually and in mixtures, on three freshwater green algae strains, the international standard strain Raphidocelis subcapitata and two native strains, Ankistrodesmus fusiformis and Tetradesmus obliquus. Bioassays were carried out according to the 72-h algal growth inhibition test. The concentration-response curve of the mixture was compared to predicted effects based on both the concentration addition (CA) and the independent action (IA) models. The two drugs tested individually were toxic to all three algal strains, with EC50 values <100 mg L-1. According to these values, the most sensitive strain was R. subcapitata (IBU = 20 mg L-1 and DFN = 8 mg L-1). The most resistant strain was T. obliquus (IBU = 74.1 mg L-1 and DFN = 92.7 mg L-1) and the A. fusiformis strain showed intermediate sensitivity (IBU = 26.7 mg L-1 and DFN = 14.6 mg L-1). The mixtures showed a synergistic effect on R. subcapitata, an additive effect on A. fusiformis, and an antagonistic effect on T. obliquus. Neither the CA nor the IA model was appropriate for predicting the toxicity of the mixtures. In conclusion, IBU and DFN showed toxic effects on the algae growth at the concentrations tested. Individual and mixed toxicity was different according to the species. These differences could be species-specific, showing the importance of including native strains in ecotoxicological studies to evaluate the potential effects of pollutants in regional aquatic environments.

Optimizing biofuel production from algae using four-element framework: Insights for maximum economic returns

This paper introduces a Four Element Strategy (FES) focused on concentration of CO2 gas (Cc,g), energy input to the process, concentration of nutrients, and the type of algal strain to maximize biofuel production (BYP) from algae strains and evaluate associated economic benefits. Two algal strains encompassing slain algae Nannochloropsis sp. (Ns), and freshwater strain Chlorella vulgaris (Cv) were used in the current study. Response Surface Methodology (RSM) and Box Behnkin Design (BBD) are integrated with a biokinetic model to explore the relationships among growth parameters in the ranges; Cc,g ∼ 0.03–20 %), Nitrogen (N) to phosphorus (P) ratio (RN/P)∼1–11, and light intensity (LI)∼ 100–400 µE m⁻² s⁻¹ with corresponding CO2 bio-fixation rate (RCO2, g L⁻¹ d⁻¹), biomass accumulation (X, g L⁻¹), and algal growth rate (µ, d⁻¹). Optimization results indicate that the most productive conditions involve LI in the range of 100–270 µE m⁻² s⁻¹, Cc,g between 0.03 % and 15 %, and RN/P of 3.5–11, achieving maximum RCO2, X, and µ at 1 g L⁻¹ d⁻¹, 6 g L⁻¹, and 1.6 d⁻¹, respectively. Further optimization using the desirability function supports achieving RCO2 of 1.2 g L⁻¹ d⁻¹, X of 1.8 g L⁻¹, and µ of 1.7 d⁻¹, with RN/P, Cc,g, and LI at 11, 4.5 %, and 200 µE m⁻² s⁻¹, respectively. Notably, Ns demonstrated higher nutrient uptake rates and BYP compared to Cv, with total production costs of $0.629/L and respective required cost coverages of $0.138 and $0.375 for Ns and Cv. This study offers a comprehensive guideline for large-scale microalgae cultivation technology (MCT) processes, providing insights into optimizing conditions for biofuel production while considering economic viability.

Microbial Biopolymers: From Production to Environmental Applications—A Review

Industrial evolution and agricultural expansion, explained by continuing population growth, have rendered enormous problems for the world throughout the past few decades, primarily because of waste generation. To reduce environmental impact and dependence on fossil fuels, scientists have explored replacing synthetic polymers with environmentally friendly and sustainable alternatives in many emergent applications. In this regard, microbial biopolymers have gained special attention. Many biopolymers originating from various strains of bacteria, fungi, and algae have been reported and their possible applications have increased rapidly. This review focuses on the wide range of microbial biopolymers, their characteristics, and factors influencing their production. The present study also describes the environmental applications of microbial biopolymers. The use of these biopolymers is very attractive as a value-added and sustainable approach to wastewater treatment. By acting as adsorbents, coagulants, and flocculants as well as filters in membrane processes, microbial biopolymers shine as promising solutions beyond conventional methods. They can be integrated into various stages of the treatment process, further enhancing the efficiency of wastewater treatment methods. Microbial biopolymer applications in bioremediation and soil stabilization are also reviewed. Several studies have demonstrated the strong potential of biopolymers in soil improvement due to their ability to minimize permeability, eliminate heavy metals, stabilize soil, and limit erosion. Challenges related to scaling up and the downstream processing of microbial biopolymers, as well as its future perspectives in environmental applications, are also discussed.

Marine microalgae Schizochytrium demonstrates strong production of essential fatty acids in various cultivation conditions, advancing dietary self-sufficiency

IntroductionPolyunsaturated fatty acids (PUFAs) are essential nutrients that humans obtain from their diet, primarily through fish oil consumption. However, fish oil production is no longer sustainable. An alternative approach is to produce PUFAs through marine microalgae. Despite the potential of algae strains to accumulate high concentrations of PUFAs, including essential fatty acids (EFAs), many aspects of PUFA production by microalgae remain unexplored and their current production outputs are frequently suboptimal.MethodsIn this study, we optimized biomass and selected ω-3 PUFAs production in two strains of algae, Schizochytrium marinum AN-4 and Schizochytrium limacinum CO3H. We examined a broad range of cultivation conditions, including pH, temperature, stirring intensity, nutrient concentrations, and their combinations.ResultsWe found that both strains grew well at low pH levels (4.5), which could reduce bacterial contamination and facilitate the use of industrial waste products as substrate supplements. Intensive stirring was necessary for rapid biomass accumulation but caused cell disruption during lipid accumulation. Docosahexaenoic acid (DHA) yield was independent of cultivation temperature within a range of 28–34°C. We also achieved high cell densities (up to 9 g/L) and stable DHA production (average around 0.1 g/L/d) under diverse conditions and nutrient concentrations, with minimal nutrients required for stable production including standard sea salt, glucose or glycerol, and yeast extract.DiscussionOur findings demonstrate the potential of Schizochytrium strains to boost industrial-scale PUFA production and make it more economically viable. Additionally, these results may pave the way for smaller-scale production of essential fatty acids in a domestic setting. The development of a new minimal culturing medium with reduced ionic strength and antibacterial pH could further enhance the feasibility of this approach.

De-risking Pretreatment of Microalgae To Produce Fuels and Chemical Co-products.

Conversion of microalgae to renewable fuels and chemical co-products by pretreating and fractionation holds promise as an algal biorefinery concept, but a better understanding of the pretreatment performance as a function of algae strain and composition is necessary to de-risk algae conversion operations. Similarly, there are few examples of algae pretreatment at scales larger than the bench scale. This work aims to de-risk algal biorefinery operations by evaluating the pretreatment performance across nine different microalgae samples and five different pretreatment methods at small (5 mL) scale and further de-risk the operation by scaling pretreatment for one species to the 80 L scale. The pretreatment performance was evaluated by solubilization of feedstock carbon and nitrogen [as total organic carbon (TOC) and total nitrogen (TN)] into the aqueous hydrolysate and extractability of lipids [as fatty acid methyl esters (FAMEs)] from the pretreated solids. A range of responses was noted among the algae samples across pretreatments, with the current dilute Brønsted acid pretreatment using H2SO4 being the most consistent and robust. This pretreatment produced TOC yields to the hydrolysate ranging from 27.7 to 51.1%, TN yields ranging from 12.3 to 76.2%, and FAME yields ranging from 57.9 to 89.9%. In contrast, the other explored pretreatments (other dilute acid pretreatments, dilute alkali pretreatment with NaOH, enzymatic pretreatment, and flash hydrolysis) produced lower or more variable yields across the three metrics. In light of the greater consistency across samples for dilute acid pretreatment, this method was scaled to 80 L to demonstrate scalability with microalgae feedstocks.

Carbon sequestration reduced by the interference of nanoplastics on copper bioavailability

Microplastics (MPs) have been recognized as a serious new pollutant, especially nanoplastics (NPs) pose a greater threat to marine ecosystem than larger MPs. Within these ecosystems, phytoplankton serve as the foundational primary producers, playing a critical role in carbon sequestration. Copper (Cu), a vital cofactor for both photosynthesis and respiration in phytoplankton, directly influences their capacity to regulate atmospheric carbon. Therefore, we assessed the impact of NPs on Cu bioavailability and carbon sequestration capacity. The results showed that polystyrene nanoplastics (PS-NPs) could inhibit the growth of Thalassiosira weissflogii (a commonly used model marine diatom) and Chlorella pyrenoidosa (a standard strain of green algae). The concentration of Cu uptake by algae has a significant negative correlation with COPT1 (a Cu uptake protein), but positive with P-ATPase (a Cu efflux protein). Interestingly, PS-NPs exposure could reduce Cu uptake and carbon Cu sequestration capacity of algae, i.e., when the concentration of PS-NPs increases by 1 mg/L, the concentration of fixed carbon dioxide decreases by 0.0023 ppm. This provides a new perspective to reveal the influence mechanisms of PS-NPs on the relationship between Cu biogeochemical cycling and carbon source and sink.

Recent Advancement Of Algal Biofuel Production And Its Potential Uses

The utilization of diverse energy sources is linked to the growth of industry, agriculture, and transportation. After the third generation of biodiesel production began, it was anticipated that algae would emerge as the most advantageous source because it not only can accumulate large amounts of lipids but also has the potential to reduce the amount of agricultural land required for the production of biofuels and enhance air quality by capturing carbon dioxide. In contrast to the price of making biodiesel from crops, the cost of algal biomass cultivation and processing poses a significant issue. The first step is to use genetic engineering to boost the lipid content of algal cells. The promotion of enhanced lipid accumulation by stressing algae is related to the second way. The third direction entails looking for new, promising strains of algae that will differ from the currently recognized strains in their ability to collect biomass more quickly, have greater Triacylglycerols [TAG] concentrations, and accumulate saturated and unsaturated fatty acids in the right ratios. By defining the evolutionary relationships within the main taxonomic groups of algae, a new technique in the search for biotechnologically relevant strains of algae has recently been developed. These investigations have resulted in a significant cost decrease for the manufacture of biofuel based on algae biomass. All of this research aimed at improving algae biofuel production and exploring additional biofuel sources is crucial.

UV mutagenesis improves growth potential of green algae in a green algae-yeast co-culture system.

It is known that co-cultivation of green algae with heterotrophic microorganisms, such as yeast, improves green algae's growth potential and carbon dioxide fixation, even under low CO2 concentration conditions such as the atmosphere. Introducing mutations into green algae is also expected to enhance their growth potential. In this study, we sought to improve the growth potential of a co-culture system of the green algae Chlamydomonas reinhardtii and the yeast Saccharomyces cerevisiae by introducing mutations into the green algae. Additionally, we performed a transcriptome analysis of the co-culture of the green algae mutant strain with yeast, discussing the interaction between the green algae mutant strain and the yeast. When the green algae mutant strain was co-cultured with yeast, the number of green algae cells reached 152 × 105 cells/mL after 7days of culture. This count was 2.6 times higher than when the wild-type green algae strain was cultured alone and 1.6 times higher than when the wild-type green algae strain and yeast were co-cultured. The transcriptome analysis also indicated that the primary reason for the increased growth potential of the green algae mutant strain was its enhanced photosynthetic activity and nitrogen utilization efficiency.

Inhibition of Polyphosphate Degradation in Synechocystis sp. PCC6803 through Inactivation of the phoU Gene.

Phosphorus is an essential but non-renewable nutrient resource critical for agriculture. Luxury phosphorus uptake allows microalgae to synthesize polyphosphate and accumulate phosphorus, but, depending on the strain of algae, polyphosphate may be degraded within 4 hours of accumulation. We studied the recovery of phosphorus from wastewater through luxury uptake by an engineered strain of Synechocystis sp. with inhibited polyphosphate degradation and the effect of this engineered Synechocystis biomass on lettuce growth. First, a strain (ΔphoU) lacking the phoU gene, which encodes a negative regulator of environmental phosphate concentrations, was generated to inhibit polyphosphate degradation in cells. Polyphosphate concentrations in the phoU knock-out strain were maintained for 24 h and then decreased slowly. In contrast, polyphosphate concentrations in the wild-type strain increased up to 4 h and then decreased rapidly. In addition, polyphosphate concentration in the phoU knockout strain cultured in semi-permeable membrane bioreactors with artificial wastewater medium was 2.5 times higher than that in the wild type and decreased to only 16% after 48 h. The biomass of lettuce treated with the phoU knockout strain (0.157 mg P/m2) was 38% higher than that of the lettuce treated with the control group. These results indicate that treating lettuce with this microalgal biomass can be beneficial to crop growth. These results suggest that the use of polyphosphate-accumulating microalgae as biofertilizers may alleviate the effects of a diminishing phosphorous supply. These findings can be used as a basis for additional genetic engineering to increase intracellular polyphosphate levels.

Isolation and characterization of microalgae strains able to grow on complex biomass hydrolysate for industrial application

Producing algae biomass economically remains one of the chief bottlenecks for commercializing algae products. The aim of this work is to identify new strains of algae that can grow on cost effective media derived from cellulosic waste streams, characterize the potential of these strains to produce compounds of high industrial value, and identify those strains capable of facile genetic transformation. Here we report, out of 45 strains initially isolated, three were selected based on their ability to efficiently grow on organic waste material (corn stover hydrolysate) as a carbon source; Chlorococcum sp., Desmodesmus sp., and Chlamydomonas debaryana. Untargeted metabolomics was performed on each strain, identifying several metabolites of high relative abundances that are of commercial interest, such as lactic acid, butane-2,3-diol, amino acids, tartaric acid, triacylglycerols, and lipid species containing different, mono- and polyunsaturated fatty acids, depending on the strain and growth condition. The strains also produced carbohydrates of industrial relevance. Chlorococcum sp. was found to be genetically transformable using standard simple transformation protocols. These results suggest that with further development, these strains could open the door to economic production of high value commercial compounds utilizing waste streams from cellulosic biomass.

The effects of different ratios of mixed feeding ofScenedesmus dimorphustoCyclotellasp. on the growth performance, pearl production ability, and biochemical components of the new shell tissue ofHyriopsis cumingii

AbstractIn order to screen out the feeding ratio of high‐quality algae strains inHyriopsis cumingii, this experiment investigated the effects of different ratio of mixed feeding of two algae strains (Scenedesmus dimorphusandCyclotellasp.) on the growth, bead production performance, trace elements, and amino acid composition of the newborn shell ofH. cumingii. The results showed that the mixed feeding of two types of microalgae with different densities had significant effects on the growth performance, bead production quality, trace elements, and amino acid composition of the newly formed shell ofH. cumingii(p < 0.05); the best body weight gain rate and shell growth rate were obtained by feedingS. dimorphus(30 × 105cell/mL) andCyclopellasp.(8 × 105cell/mL); the pearl weight gain rate, amino acid ratio, Ca2+and Mn2+content were best when feedingCyclotellasp. (16 × 105cell/mL), but there was no significant difference compared withS. dimorphus(30 × 105cell/mL) andCyclopellasp.(8 × 105cell/mL). In summary, the optimal feeding amount for the intensive breeding process ofH. cumingiiisS. dimorphus(30 × 105cell/mL) andCyclopellasp. (8 × 105cell/mL).

Progressive pollution abatement in raw dairy wastewater induced by the algae Poterioochromonas malhamensis with a high-value biomass yield

This work aimed to systematically abate in batch mode organic pollutants from raw dairy wastewater (DW) with high values of chemical oxygen demand (COD, ∼10.3 g L−1), total organic carbon (TOC, ∼2.4 g L−1), and total nitrogen (TN, ∼0.28 g L−1) by using the Poterioochromonas malhamensis algae strains. In this regard, variables such as fractions of DW (40–100%, v/v), mineral nutritional inoculum addition (0–100%, w/v) and CO2-enriched air (2–8%) were proposed to address a study in optimizing conditions with new insights on algae production. As controlled photobioreactors (PBR), a set of tubular PBRs and a pair of flat-plate PBRs (FP-PBR) surrounded by fluorescent lamps and pumped by CO2-enriched air at a flow rate of 1.4 L min− 1 per litre were used. A Box-Behnken design (BBD) for algal growing was applied using the set of tubular PBRs to get a better reduction in TOC, TN and COD, defining an optimized condition. On the best tubular PBRs-based outcome and including a holed baffles system for hydrodynamically providing a flashing light state, 9-day kinetic experiments based on a pair of FP-PBRs were performed to provide more insights on how to enhance the algal yield and COD, TN and TOC reduction. A biomass yield rate of 1.1 g L−1 per day was attained using FP-PBRs, being comparatively 10% better than tubular PBRs. Additionally, the organic pollution abatement in DW was highly significant, with a decrease of about 98%, 95%, and 92% in COD, TN and TOC, respectively, besides changing the initial bacteria diversity to another less harmful one.

Spatio-temporal techno-economic assessment of the algae-based supply chain: A proof-of-concept for North-West Europe

The growing world population is in need for new sustainable resources for healthy food, animal feed and chemicals. Algae produce a variety of compounds via conversion of CO2, nutrients, and light, and offer potential as renewable feedstock. However, producing microalgae is costly. Therefore, new economically viable supply chains must be developed. A variety of techno-economic assessments (TEA) has been performed to gain insight in the economic feasibility of algae production systems and refineries. While a TEA provides insights relevant to the technical and economic feasibility of a process, geographical conditions must be considered since the regional characteristics influence process feasibility and supply chain design.This paper presents a spatio-temporal TEA by combining a dynamic TEA model and a supply chain design optimisation model, MooV. The dynamic TEA outlines the conditions of the processes to reach a techno-economic feasible case as well as mass balances and OPEX and CAPEX of the different potential processes in the chain. MooV combines these parameters with geographic specific parameters such as the locations of activities and the characteristics of the transport network to define the optimal supply chain configuration (e.g., location and process type and capacity) based on minimal cost.The approach is demonstrated by year-round cultivation of Nannochloropsis gaditana in a horizontal tubular photobioreactor in 3 regions in North-West Europe. The analysis indicates that the cost per kg DM algae output can vary considerably (±40 %) depending on the region and the set-up of the supply chain. Including geographic characteristics as well as comparing different supply chain design options are essential to come to a viable business case. The approach can also be applied to different algae strains, different regions and different process options.

Oogamochlamys kurilensis sp. nov. (Chlorophyta, Volvocales) from the Soils of Iturup Island (Sakhalin Region, Russia).

A strain of oogamous biflagellate green alga was isolated during a study on soil algal diversity in the Russian Far East (Sakhalin Region, Iturup Island) and examined using an integrative approach. Phylogenetic analyses, based on the SSU rDNA gene, resolved the new strain as a part of the RL clade (sensu Watanabe and Nakada) within Oogamochlamydinia (Volvocales, Chlorophyceae). The strain was similar to members of the genus Oogamochlamys (parietal and massive cup-shaped chloroplasts; two apical contractile vacuoles), but was, however, distinguished from them based on the size and shape of the mature vegetative cells, the flagellar length, the presence of only one pyrenoid in both the mature vegetative cells and the zoospores, the anterior nucleus position, and the spermatozoids' shape. Although a concept of the genus Oogamochlamys has been compromised in recent phylogenetic analysis based on the SSU rDNA sequence data and its likely affinity to anisogamous Chlamydomonas allensworthii, we described the strain from Iturup Island as Oogamochlamys kurilensis sp. nov.

Johansenicoccus eremophilus gen. et sp. nov., a novel evolutionary lineage in Chlorophyceae with unusual genomic features

Background – Green algae are a diverse group of photosynthetic eukaryotes, yet are still vastly understudied compared to land plants. For many years, green algae were characterized based on their morphology and life cycles. More recently, phylogenetic and genomic analyses have been added to the phycological toolkit for a better understanding of algal biodiversity and evolutionary history. Material and methods – A desert strain of green algae was isolated from Joshua Tree National Park (JTNP) in southern California as part of a larger biodiversity survey. The alga’s nuclear rRNA genes as well as the chloroplast genome were sequenced, annotated, and analysed in addition to a morphological assessment. Results – Morphologically this strain is especially similar to Pseudomuriella and Rotundella, and its lipid profile resembles that of other soil algae, but phylogenomic analyses demonstrate that it is a distinct evolutionary lineage in Chlorophyceae. The alga exhibits several unusual genomic features, the most remarkable being its highly derived yet apparently functional nuclear rRNA genes, 18S and 28S. Both genes are GC-rich and bear many compensatory base changes to maintain a similar secondary structure to that of other green algae. The chloroplast genome has a distinct gene order and repeat arrangement from other published green algal plastomes, but contains the expected genes and also provides phylogenetically informative data. Conclusion – We conclude that the strain be placed into a new species and genus in the class Chlorophyceae, and propose the name Johansenicoccus eremophilus for this new taxon. Johansenicoccus eremophilus exemplifies science’s insufficient understanding of the range of genomic variations among inconspicuous soil algae.

The Efficiency of Moving Bed Bioreactor Carrier (MBBRC) Hybrid with Algae and Bacterial Strains for Ammonia Removal in the Rosetta Branch of the River Nile

The Efficiency of Moving Bed Bioreactor Carrier (MBBRC) Hybrid with Algae and Bacterial Strains for Ammonia Removal in the Rosetta Branch of the River Nile