Isolation and characterization of α ‐amylase encoding gene in Bacillus amyloliquefaciens PAS

Amylolytic bacteria are a source of amylase, which is an essential enzyme to support microalgae growth in the bioreactor for microalgae culture. In a previous study, the highest bacterial isolate to hydrolyze amylum (namely PAS) was successfully isolated from Ranu Pani, Indonesia, and it was identified as Bacillus amyloliquefaciens. That bacterial isolate (B. amyloliquefaciens PAS) also has been proven to accelerate Chlorella vulgaris growth in the mini bioreactor. This study aims to detect, isolate, and characterize the PAS’s α‐amylase encoding gene. This study was conducted with DNA extraction, amplification of α‐amylase gene with polymerase chain reaction (PCR) method with the specific primers, DNA sequencing, phylogenetic tree construction, and protein modeling. The result showed that α‐amylase was successfully detected in PAS bacterial isolate. The α‐amylase DNA fragment was obtained 1,468 bp and that translated sequence has an identity of about 98.3% compared to the B. amylolyquefaciens α‐amylase 3BH4 in the Protein Data Bank (PDB). The predicted 3D protein model of the PAS’s α‐amylase encoding gene has amino acid variations that predicted affect the protein’s structure in the small region. This research will be useful for further research to produce recombinant α‐amylase.

Evaluation of Microalgae Culture in PA and Commercial Urea Media

This work aimed to evaluate the growth and cost cultivation of Chlorella sp microalgae in PA and commercial urea medium solutions compared to BBM standard medium. We cultivated the microalgae Chlorella sp in BBM, PA urea, and commercial urea media, evaluating their growth for 8 days. In addition, we appraised the cost of the culture media considering the quotation of the reagents and the mass used for pilot-scale cultivation (100l). It was possible to observe the similar growth of microalgae with urea PA and BBM. The use of urea PA as a culture media for microalgae has the potential to reduce the cost of the medium by 68%. Thus, the cultivation of Chlorella in urea medium represents an alternative to reduce the production costs of biomass from this microorganism.

Uncovering Research Trends of Phycobiliproteins Using Bibliometric Approach

Phycobiliproteins are gaining popularity as long-term, high-value natural products which can be alternatives to synthetic products. This study analyzed research trends of phycobiliproteins from 1909 to 2020 using a bibliometric approach based on the Scopus database. The current findings showed that phycobiliprotein is a burgeoning field in terms of publications outputs with “biochemistry, genetics, and molecular biology” as the most related and focused subject. The Journal of Applied Phycology was the most productive journal in publishing articles on phycobiliproteins. Although the United States of America (U.S.A.) contributed the most publications on phycobiliproteins, the Chinese Academy of Sciences (China) is the institution with the largest number of publications. The most productive author on phycobiliproteins was Glazer, Alexander N. (U.S.A.). The U.S.A. and Germany were at the forefront of international collaboration in this field. According to the keyword analysis, the most explored theme was the optimization of microalgae culture parameters and phycobiliproteins extraction methods. The bioactivity properties and extraction of phycobiliproteins were identified as future research priorities. Synechococcus and Arthrospira were the most cited genera. This study serves as an initial step in fortifying the phycobiliproteins market, which is expected to exponentially expand in the future. Moreover, further research and global collaboration are necessary to commercialize phycobiliproteins and increase the consumer acceptability of the pigments and their products.

Biological Contamination: A Serious Constraint in Large Scale Microalgae Biomass Production

Microalgae biomass is a budding raw material for the origination of food, fuel, and other value-added products. However, bulk production of microalgal biomass at commercial level is a herculean task for the current microalgal mass production technologies due to the undesirable contaminations by biological pollutants. These contaminants hamstring the production of microalgae biomass by debilitating the growth of cultures, crumble the quality of biomass and sometimes may crash the whole culture. The best utilization of the microalgae biomass at industrial level could be attained by avoiding various possible biological contaminations in mass cultivation system, understanding the contamination mechanisms, and the complex interactions of algae with other microorganisms. This review explores the various types of biological pollutants, their possible mode of infection along with mechanisms, different controlling methods to maintain desired microalgae culture.

Mass transfer characteristics and biological effect of flue gas during microalgae culture

Not only carbon dioxide (CO2) but also air pollutants, such as sulfur oxides (SOx) and nitrogen oxides (NOx), are present in flue gas, and their reasonable and effective utilization is conducive to reducing the cost of microalgal biomass production. By utilizing simulated flue gas, the absorption characteristics of different components in transfer units were explored. The results showed that the presence of SO2 decreased the absorptivity of CO2, which reduced the concentration of the available carbon source for microalgal cells in the culture medium at the same pH value. Moreover, the presence of high-concentration oxygen (O2) in flue gas could improve the absorptivity of nitric oxide (NO). Scenedesmus dimorphus was cultured by using sulfur- or nitrogen-deficient culture media. The results showed that SOx and NOx in flue gas did not significantly influence the growth and biochemical compositions of microalgal cells when these gases were dissolved in water. Based on the above results and the metabolic kinetics of microalgal cells for nutrient elements, an adjustment strategy for the initial gas source when culturing microalgae with flue gas is proposed: (1) flue gas should be partially desulfurized so that the SOx and CO2 concentrations after desulfurization satisfy a certain relationship with the components; and (2) denitrification should not be performed because flue gas can be oxidized before utilization to increase the rate of utilization of NO.

Evaluate the Effect of Using Source of Nitrogen (Soaked Brown Lentils) on Chemical Composition for Marine Microalgae Nannochlorpsis oceanica

Microalgae culture media must be efficient, give high growth, meet micro-requirement, and be available. The effect of different levels of brown lentil infusion and use at [25, 50 and 75%] levels on the chemical composition (protein, carbohydrates, fatty acids, and amino acids) in N. oceanic was evaluated. Compared to the standard F/2 Guillard. The obtained results indicated that the chemical components of N. oceanica were affected by these levels. The highest protein and carbohydrate content and the highest EAA content (55.92%) were obtained using OB3 medium (75% SBL) compared to the control group (100% F/2). The highest biomass production was obtained in OB3 medium. The highest TSFA and USFA were recorded for N. oceanica by the OB3 mean. The present study recommended that it is possible to use microalgae grown on OB3 and OB2 medium as a lipid and protein inducer in aquaculture.