Bioactive metabolites produced by cyanobacteria for growth adaptation and their pharmacological properties

Cyanobacteria are the most abundant oxygenic photosynthetic organisms inhabiting various ecosystems on earth. As with all other photosynthetic organisms, cyanobacteria release oxygen as a byproduct during photosynthesis. In fact, some cyanobacterial species are involved in the global nitrogen cycles by fixing atmospheric nitrogen. Environmental factors influence the dynamic, physiological characteristics, and metabolic profiles of cyanobacteria, which results in their great adaptation ability to survive in diverse ecosystems. The evolution of these primitive bacteria resulted from the unique settings of photosynthetic machineries and the production of bioactive compounds. Specifically, bioactive compounds play roles as regulators to provide protection against extrinsic factors and act as intracellular signaling molecules to promote colonization. In addition to the roles of bioactive metabolites as indole alkaloids, terpenoids, mycosporine-like amino acids, non-ribosomal peptides, polyketides, ribosomal peptides, phenolic acid, flavonoids, vitamins, and antimetabolites for cyanobacterial survival in numerous habitats, which is the focus of this review, the bioactivities of these compounds for the treatment of various diseases are also discussed

Growth response of Heritiera simplicifolia (Mast.) Kosterm. and Scaphium macropodum (Miq.) Beumée ex Heyne due to abiotic factors in the nursery

In the earliest stage of development, non-dipterocarp wildlings require specific environmental conditions; they are only able to acclimate to harsher environmental conditions after this stage. As such, the environment acts as a limiting factor of early-stage development in non-dipterocarp shade-tolerant species. We examined the survival rates and growth rates of Heritiera simplicifolia and Scaphium macropodum from the family Malvaceae in the different sets of abiotic conditions. Three abiotic environmental factors medium type, greenhouse technique, and light intensity were varied. The experiment was conducted for six months in an area near Hulu Terengganu Hydroelectric Dam, at the edge of the Tembat Forest Reserve. Height, diameter, leaves numbers, and leaf area was recorded. Our results indicate that the wildlings preferred higher daytime relative humidity and natural air ventilation at night, and they grew more quickly under SN50 (358.74 Photosynthetically Active Radiation; PAR) than under SN70 (101.41 PAR). Subsoil supplemented with vermicompost improved wildling growth more consistently than subsoil supplemented with compost or burned mesocarp. The wildling’s height relative growth rate (HRGR) and survival were affected by all treatments. These results indicate that restoration efforts using young indigenous tree species at degraded sites, supply better growth environments and organic nutrients to the rhizosphere

Growth response of Heritiera simplicifolia (Mast.) kosterm. and Scaphium macropodum (Miq.) Beumée ex Heyne due to abiotic factors in the nursery

In the earliest stage of development, non-dipterocarp wildlings require specific environmental conditions; they are only able to acclimate to harsher environmental conditions after this stage. As such, the environment acts as a limiting factor of early-stage development in non-dipterocarp shade-tolerant species. We examined the survival rates and growth rates of Heritiera simplicifolia and Scaphium macropodum from the family Malvaceae in the different sets of abiotic conditions. Three abiotic environmental factors medium type, greenhouse technique, and light intensity were varied. The experiment was conducted for six months in an area near Hulu Terengganu Hydroelectric Dam, at the edge of the Tembat Forest Reserve. Height, diameter, leaves numbers, and leaf area was recorded. Our results indicate that the wildlings preferred higher daytime relative humidity and natural air ventilation at night, and they grew more quickly under SN50 (358.74 Photosynthetically Active Radiation; PAR) than under SN70 (101.41 PAR). Subsoil supplemented with vermicompost improved wildling growth more consistently than subsoil supplemented with compost or burned mesocarp. The wildling’s height relative growth rate (HRGR) and survival were affected by all treatments. These results indicate that restoration efforts using young indigenous tree species at degraded sites, supply better growth environments and organic nutrients to the rhizosphere

Circadian oscillations of cytosolic free calcium regulate the Arabidopsis circadian clock

In the last decade, the view of circadian oscillators has expanded from transcriptional feedback to incorporate post-transcriptional, post-translational, metabolic processes and ionic signalling. In plants and animals, there are circadian oscillations in the concentration of cytosolic-free Ca2+ ([Ca2+]cyt), though their purpose has not been fully characterised. We investigated whether circadian oscillations of [Ca2+] cyt regulate the circadian oscillator of Arabidopsis thaliana. We report that in Arabidopsis, [Ca2+]cyt circadian oscillations can regulate circadian clock function through the Ca2+-dependent action of CALMODULIN-LIKE24 (CML24). Genetic analyses demonstrate a linkage between CML24 and the circadian oscillator, through pathways involving the circadian oscillator gene TIMING OF CAB2 EXPRESSION1 (TOC1).Supported by BBSRC UK research grants BBSRC BB/D010381/1 (A.N.D.), BB/D017904/1 (F.R.) BB/M00113X/1 (H.J.H.) awarded to (A.A.R.W.), Research Studentship (K.H.) and BBSRC Industrial Case (T.H.). A Swiss Science Foundation Award (PBZHP3-123289) and the Isaac Newton Trust Cambridge (M.C.M.R. and S.A.), 678 the National Science Foundation under Grant No. MCB 0817976 (Y-C.T. and J.B.), a Royal Society Grant RG081257 and Corpus Christi College, Cambridge Junior Research Fellowship (M.J.G.), a Cordenadoria de Apoio ao Ensino Superior Brazil 25681 studentship (C.T.H.), IEF Marrie Curie (Project No. 272186) (M.C.M.R.), a Broodbank Fellowship (M.C.M.R.), a Malaysian Government Studentship (N.I.M-H.)

Anticancer agents and genetic identification of Pterospermum, an indigenous plant of Sarawak, Malaysia

In Malaysia, Pterospermum is distributed in the states of Peninsular Malaysia, Sarawak, and Sabah. For centuries, the Bidayuh tribe in Sarawak has been using an indigenous plant to cure patients diagnosed with breast cancer. The plant is called Bayur by the tribe, which is the similar local name known for several Pterospermum species in Sarawak, Sabah, and Indonesia. This study was carried out to genetically identify the indigenous plant using the core barcode loci, rbcL and matK, as well as profiling anticancer agents from this plant. Phylogenetic analyses based on both rbcL and matK loci did not show clear species resolution for the indigenous plant, however, the analyses showed consistent relationships among congeneric species of Pterospermum. Interestingly, UHPLC-QQQ/MS analysis showed the presence of anti-cancer agents in the bark extract, thus supporting the potential of the indigenous plant for breast cancer treatment

Harvesting of freshwater microalgae, Arthrospira sp. using flocculation method

Arthrospira platensis is a well-known microalgae species that is widely used as the protein and vitamin supplements to aquatic organisms, as well as a complementary dietary ingredient for human. Efficient biomass recovery or harvesting of different algal species is nevertheless a vital bottleneck for a large-scale biorefinery process. Due to its high-efficiency, cost-effectiveness and scalability, chemical flocculation was performed to harvest the biomass production of Arthrospira platensis. In the present study, the flocculation was conducted using three chemical flocculants: chitosan, aluminium sulphate, and copper (I) chloride in hydrochloric acid. The harvesting was performed and optimised using one factor at a time (OFAT) and it was found that chitosan was the most effective flocculant, with 99.96% flocculation efficiency using 90 mg/L dosages while the settling time was above 80% efficiency at the first 5th minute and remained constant until the 60th minute of the experiment. Furthermore, chitosan was studied as a biodegradable polymer and non-toxic coagulant, which may be less harmful than other chemicals