Co-production of polyhydroxybutyrate and C-phycocyanin from Arthrospira platensis growing on palm oil mill effluent by employing UV-C irradiation

Journal of Applied Phycology - Biopolymer made from bacteria is still not attractive compared to conventional commercial polymer because of the high cost of the substrate. The cyanobacterium...     

Influences of wild crucifers on life history traits and flight ability of the diamondback moth,Plutella xylostella (Lepidoptera: Yponomeutidae)

The larvae ofPlutella xylostella were fed on five wild crucifers,Capsella bursa-pastoris, Lepidium virginicum, Cardamine flexuosa, Rorippa indica, R. islandica and a crop, cabbage. The developmental period of the immature stages, adult longevity, preoviposition period, fecundity and morphometrical characters of the adults were measured. The flight activity of the adults was also measured by the tethered flight method. All the wild plants except forR. islandica were less suitable host plants than cabbage, and larvae which were fed on these less suitable plants emerged as smaller adults with shorter wings. The smaller female adults had lower fecundity but a higher flight activity. Smaller adults measured in terms of their pupal weight among individuals fed on the same host plant had longer wings. These smaller adults with longer wing flew more actively.     

Within-crown variation in the timing of leaf emergence and fall of Malaysian trees in association with crown development patterns

In aseasonal tropics, timing of leaf emergence and leaf fall may differ between the shoots of different crown parts within a tree. This is important for the efficient development of crowns because leaves should be produced as soon as enough carbohydrates are accumulated. This hypothesis was tested by investigating leaf demography over a 44-mo period for 17 Malaysian trees and comparing the timings of leaf emergence and fall between the upper and lower crowns. The timings of leaf emergence were synchronized between the upper and lower crowns, but those of leaf fall were less synchronized in most trees. Greater rates of leaf production in the upper than in the lower crowns were attributable to the differences in the number of leaves that emerged per leaf emergence event, rather than differences in frequency of leaf emergence per year. Timings of leaf emergence and leaf fall were mainly simultaneous in the upper and lower crowns, but unsynchronized leaf production and leaf fall also occurred. Such limited plasticity of leaf demography within crowns may be the result of physiological integration of branches or the compromise between the advantages of satiating herbivores and effective crown development in the trees of aseasonal tropics.     

Herbs in exercise and sports

Background

Central administration of ??-amino butyric acid (GABA) induces lower body temperature in animals in hot ambient air. However, it is still unknown whether oral GABA administration affects temperature regulation at rest in a hot environment in humans. Therefore, in the present study, we specifically hypothesized that systemic administration of GABA in humans would induce hypothermia in a hot environment and that this response would be observed in association with decreased heat production.

Methods

Eight male participants drank a 200-ml sports drink with 1 g of GABA (trial G) or without GABA (trial C), then rested for 30 minutes in a sitting position in a hot environment (ambient air temperature 33°C, relative humidity 50%).

Results

We found that changes in esophageal temperature from before drinking the sports drink were lower in trial G than in trial C (-0.046 ± 0.079°C vs 0.001 ± 0.063°C; P < 0.05), with lower heat production calculated by oxygen consumption (41 ± 5 W/m² vs 47 ± 8 W/m²; P < 0.05).

Conclusions

In this study, we have demonstrated that a single oral administration of GABA induced a larger decrease in body core temperature compared to a control condition during rest in a hot environment and that this response was concomitant with a decrease in total heat production.     

Susceptibility to photoinhibition in seedlings of six tropical fruit tree species native to Malaysia following transplantation to a degraded land

To investigate the adaptive capacity to a strong light environment when planted on degraded land, we examined photosynthetic properties in relation to photoinhibition for the sun-leaves of six tropical fruit tree species native to Malaysia before and after transplanting. The six species were: Bouea macrophylla (Bm), Callerya atropurpurea (Ca), Canarium pilosum (Cp), Cynometra cauliflora (Cc), Morinda citrifolia (Mc) and Syzygium sp. (Ssp), which produce edible fruit for endemic animals and birds, and are candidates for corridor plantations. Based on the measurements performed before transplanting, the degree of chronic photoinhibition indicated by the decrease in pre-dawn F _v/F _m was well associated with an accumulation of excessive excitation energy in PSII indicated by a decrease in photochemical quenching (qP). Among the species, Ca and Mc showed lower degrees of photoinhibition with higher qP. Higher electron transport rates (ETR) were observed with higher qP whereas there was no significant relationship between regulatory thermal dissipation (indicated by ) and qP. Energy dissipation via electron transport was suggested to be important in keeping qP high and preventing photoinhibition when compared among species. Cc and Bm showed lower ETR and higher susceptibility to photoinhibition before and after transplanting. New Cp and Mc leaves developed after transplanting showed increased area-based leaf nitrogen content (N _area) and stomatal conductance (gs) compared with those before transplanting resulting in higher light-saturated net photosynthetic rates (A _max) and ETR, and contributing to mitigate photoinhibition. In contrast to these species, Ca achieved high A _max with a water conservative manner (indicated by its relatively lower gs), where the higher carboxylation efficiency accompanied with the higher N _area allowed them to maintain relatively high A _max and ETR at lower intercellular CO₂ concentration.     

Effects of elevated pCO2 on the photosynthetic performance of the sea ice diatoms Navicula directa and Navicula glaciei

Journal of Applied Phycology - Sea ice algal communities are generally dominated by pennate diatoms, which commonly occur at the ice-water interface and in brine channels. They also make a...     

Nutritional factors influence polyhydroxybutyrate in microalgae growing on palm oil mill effluent

Journal of Applied Phycology - Bioplastic made of microalgae is attractive since it does not consume high amounts of substrate compared to bacteria. However, to make the production more feasible,...     

Transcriptomic Profiling of Rice Seedlings Inoculated with the Symbiotic Fungus Trichoderma asperellum SL2

The fungal species Trichoderma is reported to have a significant impact on the growth and physiological performance of rice plants. However, the molecular mechanisms that induce these effects remain unspecified. Using next-generation sequencing technology, this study compared the differential expression of genes in rice seedlings that had been inoculated with Trichoderma asperellum SL2 with the gene expression in seedlings that had no such inoculation. The study showed that many genes related to plant growth enhancement and physiological functioning are differentially expressed in seedlings which have been symbiotically colonized by T. asperellum SL2. In these seedlings, specific genes related to photosynthesis, RNA activity, stomatal activity, and root development were found to be up-regulated as others were down-regulated. Although the exact causal mechanisms at the molecular level remain to be identified, the presence of Trichoderma versus its absence was associated with almost ten times more significant up-regulations than down-regulations for specific genes that have been identified from previous genomic mapping. Such analysis at the molecular level can help to explain observed phenotypic effects at the organismic level, and it begins to illuminate the observed beneficial relationships expressed phenotypically between crop plants and certain symbiotic microbes.

     

Long-term changes of a waterbird community over 26 years at a Pakistani Ramsar Site

Wetlands Ecology and Management - Long-term data of local bird communities have shown changes over the past few decades due to anthropogenic pressures, especially in temperate regions. However, we...