Microbial Surface Biofilm Responds to the Growth-Reproduction-Senescence Cycle of the Dominant Coral Reef Macroalgae Sargassum spp.

Macroalgae play an intricate role in microbial-mediated coral reef degradation processes due to the release of dissolved nutrients. However, temporal variabilities of macroalgal surface biofilms and their implication on the wider reef system remain poorly characterized. Here, we study the microbial biofilm of the dominant reef macroalgae Sargassum over a period of one year at an inshore Great Barrier Reef site (Magnetic Island, Australia). Monthly sampling of the Sargassum biofilm links the temporal taxonomic and putative functional metabolic microbiome changes, examined using 16S rRNA gene amplicon and metagenomic sequencing, to the pronounced growth-reproduction-senescence cycle of the host. Overall, the macroalgal biofilm was dominated by the heterotrophic phyla Firmicutes (35% ± 5.9% SD) and Bacteroidetes (12% ± 0.6% SD); their relative abundance ratio shifted significantly along the annual growth-reproduction-senescence cycle of Sargassum. For example, Firmicutes were 1.7 to 3.9 times more abundant during host growth and reproduction cycles than Bacteroidetes. Both phyla varied in their carbohydrate degradation capabilities; hence, temporal fluctuations in the carbohydrate availability are potentially linked to the observed shift. Dominant heterotrophic macroalgal biofilm members, such as Firmicutes and Bacteroidetes, are implicated in exacerbating or ameliorating the release of dissolved nutrients into the ambient environment, though their contribution to microbial-mediated reef degradation processes remains to be determined.

Chlorophyll a concentration of Phytoplankton in Estuary Mangrove Kurau, Bangka Tengah, Indonesia

Chlorophyll a is bound within microalgae and other phytoplankton found in surface seawater. Chlorophyll is an important biochemical component in the molecular apparatus of microalgae that is responsible for photosynthesis. Photosynthesis is the process whereby phytoplankton use sunlight energy and dissolved nutrients to convert inorganic carbon to organic compounds and releasing oxygen. The objective of this research was to analyze chlorophyll a concentration of phytoplankton in estuary mangrove area in Kurau, Bangka Tengah, Indonesia. The research was carried out in estuary area that is mangrove Kurau, Bangka Tengah, Indonesia. Chlorophyll a concentration was determine using spectrophotometer methode. The chlorophyll a concentration and sea water parameters were recorded for all stations. The area was devided into four research sites. Based on the data, chlorophyll a concentrations were between 0.00587 mg/L – 0.00117 mg/L. It was considered low rate chlorophyll a concentration since lack of light penetration in the research area.

Photosynthetic activity in Devonian Foraminifera

Photosynthetically active foraminifera are prolific carbonate producers in warm, sunlit, surface waters of the oceans. Foraminifera have repeatedly developed mixotrophic strategies (i.e., the ability of an organism or holobiont to both feed and photosynthesize) by facultative or obligate endosymbiosis with microalgae or by sequestering plastids (kleptoplasts) of ingested algae. Mixotrophy provides access to essential nutrients (e.g., N, P) through feeding while providing carbohydrates and lipids produced through photosynthesis, resulting in substantial energetic advantage in warm, sunlit environments where food and dissolved nutrients are scarce. Our morphological as well as stable carbon isotope data provide, as of now, the earliest (Mid-Devonian) evidence for photosynthetic activity in the first advanced, multichambered, calcareous foraminifera, Semitextularia, from the tropical shelf of the Laurussia paleocontinent. This adaptation likely influenced the evolutionary radiation of calcareous Foraminifera in the Devonian (“Givetian revolution”), one of the most important evolutionary events in foraminiferal history, that coincided with the worldwide development of diverse calcifying marine communities inhabiting shelf environments linked with Devonian stromatoporoid coral reefs.

Internet Of Things (IoT) In Water Quality Monitoring Systems And Nutrition In Hydroponic Plants

Population is growing every year. This has an impact on the reduction of agricultural land to cultivate crops. This study aims to combine a concept that aims to expand the benefits of continuously connected internet connectivity. Based on the long term, the narrowing of agricultural land will have an impact on the scarcity of hydroponic NFT (Nutrient Film Technique) is a model of cultivation by putting the roots of plants in a shallow layer of water. The water is circulated and contains nutrients according to the needs of plants. This study combines hydroponic plants with the help of Internet of Things (IoT) technology using hydroponic planting techniques. Rooting can develop in a nutrient solution, because around rooting there is a layer of nutrient solution then the system is known as NFT. Excess water reduces the amount of oxygen and dissolved nutrients. The use of a manual measuring instrument is actually time-consuming if the owner is busy. Based on this background, the author got the idea to create a system of monitoring water quality and nutrients in hydroponic plants that can be accessed through a mobile phone.

Possibilities of using yeast in biological plant protection

The metabolic activity of yeasts, as well as their common occurrence in the environment make them a potential source of compounds that can be used in biological plant protection. The article presents health-promoting effects of yeast on plants. The pro-health effect of yeast is related to the ability to provide plants with dissolved nutrients. Yeasts can also indirectly activate plant defence mechanisms and improve plant health status. The bioremediation properties and antagonism of yeasts against numerous economically important phytopathogens play an important role here. The research is also indicated that yeasts (Pichia membranifaciens, Pichia fermentans and Meyrozyma guilliermondii) in vitro show an antagonistic activity against their phytopathogens (Alternaria alternata, Rhizoctonia solani and Colletotrichum coccodes). All the mentioned aspects of yeast activity can be useful in creating high-quality biofertilizers and biopesticides.

Chrysopogon zizanioides (vetiver).

Chrysopogon zizanioides is a grass native to Asia, now widely introduced and cultivated in tropical and subtropical regions of the world. There are two types, an infertile domesticated type and a fertile wild type. C. zizanioides can grow in a wide range of soils and climatic conditions and is very tolerant of disturbance including grazing, fire, floods and drought. This is in part due to its dense root system that can reach depths of over 3 m. All these features have made this species an excellent option for soil and water conservation (among other uses), but also make the fertile wild type of this plant a problematic invasive species. Once established, it grows very densely and has the potential to displace other plant species including other grasses. Currently, vetiver is listed as invasive in China, Fiji, Costa Rica, Anguilla and the Philippines. This species is highly efficient in absorbing dissolved nutrients such as nitrogen and phosphorous, and its dense root system can directly alter the soil structure and modify or inhibit nutrient and water acquisition by native species. Due to its deep root system, it is difficult to remove manually. It can be controlled by dense shade and by digging up the crown, and it is susceptible to glyphosate.

An integrated system for farming fish, seaweed and abalone.

The family of integrated sustainable mariculture technologies developed and implemented in Israel achieves sustainability by a holistic yet profitable approach. Filter feeders and algae use sunlight to convert polluted effluents from fish and shrimp culture into profitable products, while restoring water quality. The results are higher yield and income per feed and water inputs. The technologies are generic and modular, adaptable for fish or shrimp culture at any level of intensification. Marine fish, shrimp, seaweed, oysters, clams, abalone and sea urchins already grow on several farms, and others are planned. Mariculture effluents pass or recirculate through algae biofilter ponds stocked with phytoplankton or seaweed. These algae biofilters efficiently extract dissolved nutrients, carbon dioxide (CO2) and biological oxygen demand (BOD) from the effluent and recharge the effluent with dissolved oxygen (DO). The nutritious algae produced are marketed or nourish algivores - bivalves, brine shrimp, abalone or sea urchin. The integrated mariculture is profitable because of the sales of the biofilter organisms - shellfish and seaweed, and the greatly reduced environmental impact.

Nutrient Export and Periphyton Biomass in a Stream-Lake Basin from the Patagonian Andean Region

We characterized how land use influenced dissolved nutrients and periphytic algal biomass in an Andean basin from Northwest Patagonia. Nutrient export, especially dissolved inorganic nitrogen increased with human population density. However, no correlation between nutrient concentration and algal biomass was found, which could instead be limited by light availability. Our results suggest that local N-limited ecosystems are liable to eutrophication by increased demographic pressure and that alternative wastewater treatment strategies are necessary for sustainable growth.