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Diatoms are unique photoautotrophic microalgae, in which the outer cell wall is composed of a silicified skeletal structure called frustules. These microalgae have relatively higher generation times and growth rates than other groups of microalgae. An interesting feature is that the diatom can accumulate a greater volume of heavy metals in its frustule, and have some specialized proteins and enzymes for detoxification of heavy metals. In the present study, a centric diatom was isolated from the Adyar River, Chennai, Tamil Nadu, India, and morphologically identified as Cyclotella atomus Hust. Based on the bioaccumulation study on the treatment with TiO2 with culturing the diatom Cyclotella atomus and SEM-EDAX analysis it has resulted that, the Ti accumulated on the frustules of the diatom. Therefore, biogenic accumulation and fabrication of Titanium frustules in diatom have advantages in enhancing the efficiency of solar cells.

Marine seaweeds are nature’s largesse resource in human well-being. Seaweed’s contribution to the food industry is being widened for its rich source of essential vitamins, minerals, and PUFA. ‘Nori’ is a dried sheet of red seaweed Porphyra sp. used to make ‘sushi’ a renowned cuisine in Japan, and other Southeast Asian countries. In this present study, commercial-grade ‘Nori’ was extracted and fractionated with different solvents, and subjected to evaluate the cytotoxic activity on human ovarian tetracarcinoma cells (PA1). As a result, the ethyl acetate fraction was found effective in inhibiting the proliferation of human ovarian cancer cells with an IC50 value of 41.1 µg/mL. The main component responsible for anticancer activity was determined as a sesquiterpene lactone Tatridin B (3h-cyclodeca[b]furan-2-one, 4,9-dihydroxy-6-methyl-3,10-dimethylene-). Moreover, it was found effective in inhibiting NSD2, an important and recently proposed biomarker for several types of cancer. This is a hitherto report on the presence of this compound in ‘Nori’ showing potent anticancer activity on human ovarian tetracarcinoma (PA1).

Seagrasses are one of the groups of marine angiosperms widely distributed all over the coastal regions. The seagrass ecosystem is very productive and traditionally used for a variety of therapeutic purposes. The present study aimed to investigate the in-vitro anticancer activity against malignant melanoma (A375), lung carcinoma (A549), cervix adenocarcinoma (HeLa) and colorectal adenocarcinoma (HT29) cell lines and phytochemical screening of ethyl acetate fraction of Halodule uninervis (EAF) from Mandapam coastal region, Rameswaram, Gulf of Mannar, India. The qualitative phytochemical analysis of EAF was performed as followed by standard methods. EAF showed the presence of alkaloids, steroids, terpenoids, flavonoids, phenols and quinones. The total flavonoid and phenolic contents of EAF were determined using the spectrophotometric method. The total flavonoid and phenolic contents showed 67.33 ± 1.52 mg QE/g dried fraction and 87.75 ± 1.39 mg GAE/g dried fraction, respectively. Gas Chromatography-Mass Spectrometry (GC-MS) analysis of EAF shows the presence of 23 phytochemical compounds. The in-vitro anticancer activity of EAF was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, AO/EtBr staining and DNA fragmentation assay for 24 hours treatment. The IC50 values of EAF showed 91.64 ± 1.61 μg, 269.16 ± 5.17 μg, 845.16 ± 36.09 μg and >1000 μg against A549, HeLa, HT29 and A375 cells, respectively. Followed by reference standard, Doxorubicin showed IC50 values of 17.53 ± 0.07 μg, 14.12 ± 0.30 μg, 17.44 ± 0.25 μg and 21.44 ± 0.40 μg against A549, HeLa, HT29 and A375 cells, respectively. AO/EtBr and DNA fragmentation assay confirmed the occurrence of apoptosis in the A549 cell line after the treatment of EAF. These results suggest that H. uninervis is a promising source of cytotoxicity against A549 cells and could be considered as a source for new lead structures to the development of new anticancer drugs.

The present study was evaluated for the proximate composition (moisture, carbohydrate, protein, and lipid contents) of two seaweedsGracilaria corticata(Rhodophyceaen) andHalimeda opuntia(Chlorophycean). Phylogenetic analysis based on the SSU (small subunit) rRNA ascertained their molecular identification. The results showed that the carbohydrate (5.72 +/- 0.05 g/100 g), protein (42.38 +/- 0.08 g/100 g), and total lipids (10.09 +/- 0.06 g/100 g) are elevated inG. corticatawhen compared toH. opuntia. H. opuntiahad a protein content of 3.51 +/- 0.072 g/100 g and higher moisture content (95 +/- 0.45 g/100 g). The methanolic extracts ofG. corticataandH. opuntiawere used to examine the antioxidants (viz. TPC, TFC, DPPH, and FRAP) and antidiabetic (alpha-glucosidase) properties. The antioxidant results of the methanolic extract ofG.corticataexhibited a higher amount of phenolic compounds (13.37 +/- 0.01 mg GAE/g dry wt.) compared toH. opuntia. But in the case of flavonoids,H.opuntiacontained a slightly higher amount of quercetin equivalent 9.56 +/- 0.26 mg/g dry wt. In FRAP,H.opuntiashowed an elevated level (62.02 mg TE/g dry wt). DPPH scavenging activity in the seaweed extracts were recorded in the following order:H.opuntiaandG.corticata. The amino acid content ofH.opuntiawas 0.097 +/- 0.56 (mg/g) and 0.086 +/- 0.42 (mg/g) was recorded inG.corticata. [GRAPHICS.] University of Algarve, Portugal info:eu-repo/semantics/publishedVersion

Background Microalgae grown under different nutrient deficient conditions present a good source of natural lipids with applications for several types of biofuels. The expression of acetyl-CoA carboxylase gene can further provide an insight to the mechanisms leading to enhanced lipid production under such stresses. In this study, two nutrients viz. nitrogen and phosphorus were modulated to see its effect on lipid productivity in selected cyanobacteria and its correlation with Accase followed by molecular dynamics simulation. Results Selected cyanobacteria viz. Oscillatoria sp. (SP8), Anabaena sp. (SP12), Anabaena sp. (SP13), Microcoleus sp. (SP18), and Nostoc sp. (SP20) varied in their ability to accumulate lipids which ranged from a lowest of 0.13% in Anabaena sp. (SP13) to the maximum of 7.24% in Microcoleus sp. (SP18). Microcoleus sp. (SP18) also recorded highest lipid accumulation at both N (6 mM NaNO3) and P (0.20 mM K2HPO4) limiting conditions. The overall expression of accD was found to be upregulated in both Oscillatoria sp. (SP8) and Microcoleus sp. (SP18) for all nitrogen concentrations but was differentially regulated with both positive and negative induction under phosphorus stress conditions. Maximum induction was observed in Microcoleus sp. (SP18) at 0.20 mM K2HPO4. The obtained 3D structure of SP8 protein (21.8 kDa) showed six alpha helices, while SP18 protein (16.7 kDa) exhibited four alpha helices and four beta sheets. The phi (ϕ)/psi(ψ) angles of the amino acid residues observed in Ramachandran plot analysis showed that both SP8 and SP18 proteins were highly stable with more than 90% amino acids in allowed regions. The molecular dynamics simulation results also indicated the stability of ligand-bound protein complexes. Conclusion It has been demonstrated that cyanobacterial isolates are affected differently by nutrient limitation leading to variation in their lipid productivity. The same has been revealed by the behavior of accD gene expression which was regulated more by nutrients concentrations rather than the organism. However, the ligand-bound protein complexes were stable throughout MD simulations. Electronic supplementary material The online version of this article (doi:10.1186/s13068-017-0776-2) contains supplementary material, which is available to authorized users.

Conventional methods of polyethylene degradation including incineration, landfill and chemical treatment are lethal to the neighboring environment by causing hazardous effects on living organisms. A better solution for the complete degradation of polyethylene has not yet been formulated. However, to solve this global issue biological mode of polyethylene degradation may be evaluated and developed in the upcoming future. In this research investigation, microalgae like green algae, blue-green algae and diatoms were isolated from the domestic polyethylene bags dumped in the suburban water bodies and studied for its potency on deterioration of polyethylene. The dumped waste polyethylene bags were collected from three different sites of (Maduravoyal, Vanagaram and Poonamallee) Chennai, Tamil Nadu, India. Colonized mat of microalgae were isolated from the polyethylene sheets and the most dominant three different groups of microalgae were selected for the biological treatment of LD (low density) and HD (high density) polyethylene sheets. The most dominant microalgae were Scenedesmus dimorphus (Green microalga), Anabaena spiroides (blue-green alga) and Navicula pupula (Diatom). The T. S. (Transverse section) of polyethylene sheet has shown the proliferation of microalgae in both outer and inner sides of the polyethylene sheet and the erosion cum degradation can be seen obviously. The biological treatment of the selected microalgae on the LD and HD polyethylene sheets with their respective culture media resulted that the microalgae proliferated more on the LD than the HD polyethylene sheets followed by the highest percentage of degradation was obtained from Anabaena spiroides treatment (8.18%). Similarly, among the three microalgal groups treated over the LD polyethylene sheets. The scanning electron microscopical study reveals that the degradation was obviously evident in the treatment of LD polyethylene sheets using the microalga Anabaena spiroides (filamentous blue-green alga) and was found to grow feasibly rather than the other microalgae.

Additional file 1: Table S1. Primers used for gene specific amplification and quantitative real time PCR analysis of Acetyl-CoA carboxylase (accD) gene (Y = C/T, R = A/G, N = A/T/G/C, H = A/C/T, W = A/T, D = A/G/T). Table S2. Relationship of accD gene of test organism as done by BLAST search results and the accession numbers. Table S3. ProtParam analysis for fetching the physicochemical parameters of predicted protein of Oscillatoria sp. (SP8). Table S4. Secondary structural features of SP8 protein. Table S5. ProtParam analysis for fetching the physicochemical parameters of predicted protein of Microcoleus sp. (SP18). Table S6. Secondary structural features of SP18 protein. Figure S1. Amplification of accD gene in SP8 and SP18. Figure S2. protein structure of Oscillatoria sp. (SP8). Figure S3. protein structure of Microcoleus sp. (SP18).

The use of chemical advances to mechanical research, improvement, and assembling has turned into a critical field. Since the creation of rough rennet in 1874, a few catalysts have been marketed, and utilized for restorative, supplementary, and different applications. Late headways in biotechnology now enable organizations to create more secure and more affordable chemicals with upgraded intensity and specificity. Cancer prevention agent catalysts are developing as another expansion to the pool of modern chemicals and are outperforming every single other compound as far as the volume of research and creation. In the 1990s, a cell reinforcement chemical-superoxide dismutase (SOD) was brought into the market. In spite of the fact that the catalyst at first demonstrated extraordinary guarantee in restorative applications, it didn't perform up to desires. Therefore, its utilization was restricted to nontranquilize applications in people and medication applications in creatures. This survey compresses the ascent and fall of SOD at the mechanical level, the purposes behind this, and potential future push territories that should be tended to. The audit likewise concentrates on other modernly significant parts of SOD, for example, mechanical significance, catalyst designing, generation procedures, and process streamlining and scale-up.

Casuarina equisetifolia is one of the ecologically and economically important tropical coastal trees nodulated by nitrogen-fixing actinomycete Frankia and forming symbiotic associations with both ecto- and endomycorrhizal fungi. The present study aims at the ultrastructural study of interactions between C. equisetifolia, Frankia, and mycorrhiza. C. equisetifolia seeds were sterilised and germinated under in vitro condition. The seedlings were transferred to conical flasks containing vermiculite and saw dust with Hoagland's solution. After 30 days, the inoculum of AM fungus--Glomusfasciculatum (A), ectomycorrhizal fungus-Pisolithus tinctorius (E) and actinorhizal Frankia (F) were inoculated individually and in various combinations, (A+E), (A+F), E+F) and (A+E+F). After 90 days, the experimental plant roots and nodules were harvested for assessment of growth characters of mycorrhizal and actinorhizal association by light and scanning electron microscope methods. C. equisetifolia roots were infected with arbuscles and vesicles of G. fasciculatum; P. tinctorius formed fungal sheath but no Hartig net. Large number of cortical cells were seen infected with Frankia, hyphae of Frankia were frequently seen penetrating from cell to cell directly through cell walls and Frankia occupied majority of the cell volume.