Higher Maximum Biomass Research Articles

Effects of temperature and initial pH on the growth of four dominant cyanobacteria species in biological soil crusts.

Biological soil crusts are of great significance for environment health and sustainable development in arid and semi-arid areas. Cyanobacteria, Microcoleus vaginatus, Scytonema sp., Nostoc sp., and Anabaena sp. are the dominant species in microbial community of biological soil crusts worldwide. Considering their broad application prospect, it is meaningful to cultivate them extensively. We examined the effects of temperature (10, 20, 25, 30, 35 ℃) and initial pH (4, 6, 8, 10, 12) on biomass and solution pH towards the four species of cyanobacteria with liquid culture in laboratory. The results showed that the biomass of the four cyanobacterial species grew slowly under 20 ℃, and that all species could grow in 25-35 ℃, with the highest growth rate at 25 and 30 ℃. The optimum culture temperature of different cyanobacterial species was slightly different. The optimum culture temperature was 25-30 ℃ for Scytonema sp. and Nostoc sp., and 30 ℃ for M. vaginatus and Anabaena sp. The four cyanobacterial species had a strong ability to adjust solution pH and proliferate in five different initial pH conditions. The highest maximum biomass and specific growth rate were recorded in the culture environment with initial pH of 4, while the lowest maximum biomass and specific growth rate were observed in initial pH of 12. Our results would provide scientific basis for the propagation of dominant cyanobacteria in biological soil crusts.

Comparison of single strain, natural algal communities and a native algal bloom: Application for wastewater treatment and biomass generation in cassava biogas effluent

AbstractPhycoremediation of Chlorella sorokiniana P21 as indigenous strain (P21), four algal communities from different wastewater treatment ponds (P1, P2, P3 and P4) and a native algal bloom (CTRL) were examined to treat cassava biogas effluent wastewater (CBEW) and generate algal biomass. All cultures showed higher biomass production in unsterilized CBEW than in the sterilized CBEW, whereas nutrient removal efficiency was not significantly different in both conditions for all cultures. Verhulst kinetics models showed P21 culture has the highest maximum biomass (1440.94 mg L−1), whereas P3 showed the highest growth rate (0.68 day−1). The removal efficiencies of these cultures for nitrate, phosphate and chemical oxygen demand were above 75%. Iron coagulants attained the removal to be more than 90% only in P21 culture. Indigenous and algal community cultures had similar potencies to treat wastewater, and thus, this result showed vast potency of phycoremediation using various inoculum sources.

Coupling effects of reduced nitrogen, phosphorus and potassium on drip-irrigated cotton growth and yield formation in Northern Xinjiang

ABSTRACT To elucidate the effects of nitrogen (N), phosphorus (P) and potassium (K) on cotton growth and yield, field studies with four N treatments (506, 402.5, 299 and 195.5 kg ha−1 designated as N1, N2, N3 and N4, respectively) and four managements (M) of P and K application, designated as PK-M1 (total P and K applied at squaring stage (SS)), PK-M2 (25%:75% at SS and bloom-bolling stage (BS)), PK-M3 (50%:50% at each stage), PK-M4 (75%:25% at SS and BS) were conducted in 2018 and 2019. Results are shown in reproduction growth, PK-M3 under N treatments had the highest maximum biomass (K’) and fastest speed of biomass accumulation (Vmax), and N2PK-M3 obtained higher K’ and Vmax than others, followed by N3PK-M3. The average boll number, boll weight and yield in N2 were greater than others, and N3 with a decrease of 3.4–6.1% in average yield over N2. Although the yield in N3PK-M3 reduced by 1.4–1.5% compared to N2PK-M3 (losses about $8–32 per hectare), the fertilizer input decreased about $60–63 per hectare than N2PK-M3. Results suggest that 50% PK application ratio during SS and 50% during BS coapplied with proper reduced N application rate could compensate the yield loss by maintaining a higher level of reproduction biomass accumulation.

Macro Alga Community in Wakal Village Beach, Central Maluku District

Algae communities in life in the marine environment, among others, are used by various types of fish and other organisms as a place to live, forage, and spawn. Some types of macro algae also contain lime which plays a role in building coral reefs. As for humans, algae are used as food ingredients, both directly as vegetables and processed first as gelatin. The purpose of this study was to describe the composition of macro algae species found, to calculate density, population size, maximum biomass, and distribution patterns of macro algae communities in the coastal waters of Wakal Village. Taking algae macro samples is done by using the Linear Squares Transect method. Identification results of macro algae samples found 15 species classified into 3 divisions, 3 classes, 9 orders, 10 families, and 12 genera. The total density of macro algae species by individual is 2.86 ind / m2, with the highest density of species owned by Padina minor species and lowest Gelidiella acerosa, Galaxaura filamentosa, Halimeda opuntia, Ulva conglobata, Hypnea pannossa, Hypnea valentiae, and Acanthophora specifera. The total density of macro algae species based on biomass is 68.48 gr / m2 where Padina minor has the highest biomass density value and the lowest is Acanthophora specifera. The total population of macro algae based on individuals is 7.71 ind / ha, with Padina minor having the highest value of the highest and lowest population Gelidiella acerosa, Galaxaura filamentosa, Halimeda opuntia, Ulva conglobata, Hypnea pannossa, Hypnea valentiae, and Acanthophora specifera. The total macro population of algae based on biomass is 184.90 gr / ha with the highest biomass owned by species Padina minor and the lowest is Acanthophora specifera. The total maximum macro biomass of algae is 1008.18 gr / ha with the highest maximum biomass owned by species Padina minor and the lowest maximum biomass is owned by the species Acanthophora specifera. The pattern of macro spread of algae in Wakal Village is in groups (Ip = 0.5).

Growth and biomass turnover of Hydrocharis dubia L. cultured under different nutrient conditions

AbstractGrowth of a floating‐leaved plant, Hydrocharis dubia L., was examined under varying nutrient conditions between 0.3 and 30 mgN l−1 total inorganic nitrogen. H. dubia plants cultured under the most nutrient‐rich condition showed the highest maximum ramet density (736 m−2), the highest maximum biomass (80.4 g dry weight m−2), and the highest total net production (185 g dry weight m−2 in 82 days). Plants under nutrient‐poor conditions had a relatively large proportion of root biomass and a small proportion of leaves with a long life span.Compared with other floating‐leaved and terrestrial plants, the maximum biomass of H. dubia was relatively small. This, and the rapid biomass turnover, was related to the short life span of leaves (13.2–18.7 days) and large biomass distribution to leaves.

The growth of four species of Azolla as affected by temperature

The growth of 22 strains of Azolla pinnata R. Br., 3 strains of A. filiculoides Lam. and one strain each of A. mexicana Presl and A. caroliniana Willd. was tested separately in liquid culture media kept in controlled, artificial light (30 klux) growth cabinets. Three temperature levels were used: 33°C (37/29°C day/night), 29°C (33/25°C) and 22°C (26/18°C)/ Photoperiod was 12 h a day. For most A. pinnata strains (except three) and an A. mexicana strain the maximum weekly relative growth rate was higher at 33°C than at 22°C, but not for A. filiculoides and A. caroliniana. The highest value of maximum relative growth rate corresponded to 1.9 doubling days and in most strains this occurred in the first week. As the plants grew, the growth rate slowed down more severely at higher temperatures. The maximum biomass was higher at 22°C than at 33°C in all strains. At 22°C, it took 30–50 days to attain maximum biomass and the highest value was 14 g N m −2 or 320 g dry m −2 by A. caroliniana, followed by 12 g N m −2 or 290 g dry wt. m −2 by one strain of A. filiculoides. At 29°C, the maximum biomass was attained in 20–35 days. The highest value was 6.3 g N m −2 or 154 g dry wt. m −2 by A. caroliniana. At 33°C, most A. pinnata strains gave a maximum biomass of less than 4 g N m −2 after 13–23 days, while some strains grew up to 30 days, resulting in a higher maximum biomass. The highest maximum biomass at 33°C was 5.5 g N m −2 or 140 g m −2 dry wt. by A. pinnata from Cheng Mai while the maximum biomass of A. filiculoides and A. caroliniana was much less. Azolla filiculoides requires lower temperature than other species for its growth. Azolla pinnata has the best tolerance to high temperatures among the four species. Azolla mexicana could not be discriminated from A. pinnata in its response to temperature. Azolla caroliniana may keep an intermediate position between A. filiculoides and A. pinnata in temperature response. The formation of ammonia in the medium was examined and it occurred mostly under stationary growth conditions, but, at 33°C, some strains of A. pinnata and A. mexicana released or formed ammonia at 0.3–0.8 μg N ml −1 per week during their initial exponential growth stage.