Antiviral Cyanometabolites—A Review

Global processes, such as climate change, frequent and distant travelling and population growth, increase the risk of viral infection spread. Unfortunately, the number of effective and accessible medicines for the prevention and treatment of these infections is limited. Therefore, in recent years, efforts have been intensified to develop new antiviral medicines or vaccines. In this review article, the structure and activity of the most promising antiviral cyanobacterial products are presented. The antiviral cyanometabolites are mainly active against the human immunodeficiency virus (HIV) and other enveloped viruses such as herpes simplex virus (HSV), Ebola or the influenza viruses. The majority of the metabolites are classified as lectins, monomeric or dimeric proteins with unique amino acid sequences. They all show activity at the nanomolar range but differ in carbohydrate specificity and recognize a different epitope on high mannose oligosaccharides. The cyanobacterial lectins include cyanovirin-N (CV-N), scytovirin (SVN), microvirin (MVN), Microcystisviridis lectin (MVL), and Oscillatoria agardhii agglutinin (OAA). Cyanobacterial polysaccharides, peptides, and other metabolites also have potential to be used as antiviral drugs. The sulfated polysaccharide, calcium spirulan (CA-SP), inhibited infection by enveloped viruses, stimulated the immune system’s response, and showed antitumor activity. Microginins, the linear peptides, inhibit angiotensin-converting enzyme (ACE), therefore, their use in the treatment of COVID-19 patients with injury of the ACE2 expressing organs is considered. In addition, many cyanobacterial extracts were revealed to have antiviral activities, but the active agents have not been identified. This fact provides a good basis for further studies on the therapeutic potential of these microorganisms.

Spatial and temporal patterns of phytoplankton composition in Zobe Reservoir, Dutsinma, Katsina State, Nigeria

The abundance and distribution of phytoplankton algae in Zobe Reservoir was studied from using (3) sampling stations for a period of eight (8) months.The water was also analysed for Physicochemical attributes which includes Temperature, pH, Dissolved Oxygen, Biological Oxygen Demand, Nitrate-Nitrogen, Phosphate-Phosphorus, Total Dissolved Solids, Transparency and Electrical Conductivity using standard methods. Results showed that the values of physicochemical parameters recorded were of a typical tropical region. Station ‘B’ (middle) has highest number of organisms (284 org/l), followed by station ‘C’ (221 org/l), the least was recorded in station ‘A’ (162 org/l). Physicochemical attributes did not vary significantly among the stations. Four (4) classes of algae were identified which were dominated by Chlorophyta 386(57.87%), followed by Cyanophyta 126 (18.89%), and the least was Bacillariophyta 47(7.05%) represented byTabellaria flocculosa. There were generally high number of algal organisms (Chlorophyta, Cyanophyta, Euglenophyta and Bacillariophyta) observed during the dry season than in the wet season. However, Spirogyra sp.had the highest number of occurrence in all stations (204 org/l) followed by Euglena sp. (109 org/l)and the least was Oscillatoria agardhii (22 org/l). There was positive significant correlation (P<0.05) between algae and physicochemical attributes of the reservoir. The study showed that the reservoir was not polluted and the water is safe for domestic use since the number of harmful algal cells recorded were relatively low which were within the standardof World Health Organization for safe water (WHO, 2003). Keywords: Phytoplankton, Zobe, Reservoir, Pollution, Cyanophyta.

Cloning cDNA sequence coding the KSA-1 lectin from red alga Kappaphycus striatum cultivated in Vietnam

The red alga Kappaphycus striatum is economically important food species and extensively cultivated in Vietnam. This cultivated alga may thus now contribute as a source of not only carrageenan, but also other bioactive compounds for biochemical and medicinal uses. KSA-1 lectin from this alga has been evaluated for biochemical properties, including high-mannose binding specificity, N-terminal amino acid sequence and molecular mass. In this study, we have cloned the cDNA clone encoding the lectin KSA-1. The full-length sequence of cDNA clone of KSA-1 lectin encoded a polypeptide of 268 amino acids including initiating methionine, with four tandemly repeated domains of about 67 amino acids, and sharing 43% sequence identity. The primary structure and the amino acid residues interact with mannopentaose core structure per a repeat domain of the KSA-1 lectin highly resemble and match those of anti-virus the lectin family in lower organinsms, including bacteria [BOA from Burkholderia oklahomensis EO147, MBHA from Myxococcus xanthus and PFA from Pseudomonas fluorescens Pf0-1], cyanobacteria [OAA from Oscillatoria agardhii] and red algae [ESA-2 from Eucheuma serra, EDA-2 from Eucheuma denticulatum, KAA-1 and KAA-2 from Kappaphycus alvarezii and KSA-2 from K. striatum]. Analysis of predicted secondary structure of KSA-1 showed twenty β-strands. Each repeated domain comprises the five β-strands and matches with number of β-strands of BOA lectin. Therefore, the red alga K. striatum could be a good source for application in biomedicine and biochemistry as materials for production of the functional lectin(s).

Genus Oscillatoria Vaucher (Cyanoprokaryota) in Maldah District, West Bengal, India

Genus Oscillatoria Vaucher is the ubiquitous Cyanoprokaryote, growing in almost all habitats in fresh-water ecosystem like bils, dighis, lakes, ponds, wetlands, and marine water system like - salt marshes and pans, estuaries, brackish waters and ocean. It also occurs on inter-tidal rocks, snow and even in cold lakes underneath 5 m of ice pack as well as in thermal springs. During systematic investigations recorded altogether 25 species, 4 variety and 2 forms from Maldah District viz. Oscillatoria acuta Bürhl and Biswas, Oscillatoria agardhii Gomont, Oscillatoria amoena (Kütz.) Gomont, Oscillatoria amphibia C.Agardh ex Gomont, Oscillatoria amphigranulata Goor, Oscillatoria angusta Koppe, Oscillatoria chalybea G.Mertens ex Gomont, Oscillatoria formosa Bory ex Gomont, Oscillatoria formosa f. loktakensis Brühl and Biswas, Oscillatoria geitleriana Elenkin, Oscillatoria geminata Menegh. ex. Gomont, Oscillatoria limnetica Lemmerm., Oscillatoria limosa C.Agardh ex Gomont, Oscillatoria minnesotensis Tilden, Oscillatoria okenii C.Agardh ex Gomont, Oscillatoria ornata var. crassa C.B.Rao, Oscillatoria perornata f. attenuata Skuja, Oscillatoria princeps Vaucher ex Gomont, Oscillatoria prolifica Gomont, Oscillatoria proteus Skuja, Oscillatoria pseudogeminata var. unigranulata Biswas, Oscillatoria quadripunctulata Brühl and Biswas, Oscillatoria raoi DeToni, Oscillatoria redekei Goor, Oscillatoria rubescens DC. ex Gomont, Oscillatoria splendida Grev. ex Gomont, Oscillatoria subbrevis Schmidle, Oscillatoria tenuis C.Agardh ex Gomont, Oscillatoria tenuis var. natans Gomont, Oscillatoria tenuis var. tergestina Rabenh. ex Gomont and Oscillatoria willei N.L.Gardner. However, Oscillatoria subbrevis Schmidle, Oscillatoria tenuis C.Agardh ex Gomont are the most common species followed by Oscillatoria amphigranulata Goor, Oscillatoria acuta Bürhl and Biswas, Oscillatoria amphibia C.Agardh ex Gomont, Oscillatoria amphigranulata Goor in water bodies of Malda District. Oscillatoria redekei Goor is reported new from India.

Dynamics Of Environmental Factors In Relation To Phytoplankton Species In A Pond Of Old Dhaka, Bangladesh

The relationship between different environmental factors and abundance of phytoplankton species was studied for one year in a pond of old Dhaka named Sikkatuli pond. The range of annual mean of different variables in the pond was air and water temperatures 20 - 31.75˚C, secchi depth 21 - 54 cm, pH 7.39 - 8.3, alkalinity 3.9 - 9.2 meq/l, conductivity 484.5 - 2273.34 μS/cm, DO 3.35 - 8.33 mg/l, TDS 224.67 - 380.5 mg/l, SRS 12.03 - 79.93 mg/l, NO3-N 0.18 - 0.435 mg/l, SRP 0.33 – 4.28 μg/l, chlorophyll a 196.08 - 362.76 μg/l and phaeopigment 30.51 - 212.2 μg/l. During the investigation Cryptomonas erosa var. reflexa, Rhodomonas lens, Cyclotella comensis, Merismopedia gluaca, Euglena acus, Lyngbya limnetica, Chlorella vulgaris, Arthrospira platensis, Trachelomonas volvocina, Oscillatoria agardhii, Synechocystis aquatilis, Pelonema aphane and Peridinium sp. were found to be dominant phytoplankton. Pearson correlation showed that only alkalinity correlated with phytoplankton at 5% significant level. RDA orientation showed that air temperature, water temperature, secchi depth, chl a and pheopigment concentration are the important environmental factors. RDA ordination plot also showed that phytoplankton species of Pelonema aphane and Peridinium sp. were negatively correlated with secchi depth. Negative correlation was also observed between Trachelomonas volvocina and water temperature. Asiat. Soc. Bangladesh, Sci. 42(2): 169-175, December 2016

Optimization of physical parameters for phycobiliprotein extracted from Oscillatoria agardhii and Synechococcus nidulans / Oscillatoria agardhii ve Synechococcus nidulans türlerinden fikobiliprotein ekstraksiyonu için fiziksel parametrelerin optimizasyonu

Objective: Physical process parameters play a major role in the cultivation of cyanobacteria to provide high yield. The aim of this study was to optimize physical parameters such as light intensity and agitation rate which might affect the phycobiliprotein formations for cyanobacterial strains of Oscillatoria agardhii and Synechococcus nidulans using response surface methodology.Methods: The cyanobacterial strains were cultured in 250 mL flasks containing 100 mL of EM medium in orbital shaking incubator under the temperature of 22±2°C at different light intensities and agitation rates for 10 days. The experimental design was carried out using 2Results: The optimization solution of O. agardhii (approximately at 156 rpm under the light intensity of 65 μmol photons mConclusion: High agitation rate stimulated the faster growth than increased the light intensity for the growths of cyanobacterial strains.