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In order to determine effects of chicken and cattle manures in culture of Chlorococcum, an experiment was designed in six treatments including; 0.1, 0.4, 0.8 g/l of chicken manure and 0.1, 0.4, 0.8 g/l of cattle manure as completely randomize design with three replicates for 28 days. Results showed that the mean maximum density (87.1 × 10⁵ cell/ml), specific growth rate (0.054 day^-1), algal dry biomass (0.644 g/l), and chlorophyll a (9.42 mg/l) were obtained with 0.8 mg/l chicken manure. In order to compare performance of these manures with other culture media, second experiment with five treatments including; BBM (control) (Bold’s Basal Medium), BBM + soil extract, 0.8 g/l chicken manure, 0.8 g/l cattle manure and mixture of all treatment (BBM, BBM + soil extract, chicken manure and cattle manure) was designed as completely randomize design with three replicates for 15 days. Comparative results showed that BBM + soil extract had highest algal density (11.6 x 10⁶ cells/ml), highest algal dry biomass (0.81 mg/ml), maximum SGR (0.13 /day), highest chlorophyll a (10.15 mg/l) and minimum doubling time (4.97 days). In conclusion, performance of BBM + soil extract was better in terms of biomass and growth parameters of Chlorococcum.

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Recently the previous Caspian ecosystem is in a catastrophic condition which caused changes in the absolute and relative abundance of the commercially important Caspian kutum (Rutilus frisii kutum) in Iranian waters. The paper presents estimates of yield-per-recruit and spawning biomass-per-recruit under various harvest strategies of F_max, F_0.1, F_30%. It proposes a method for estimating acceptable biological catch (ABC) that accounts for large differences in the quality and quantity of information and available data. The current average Y/R (with F=0.61/y, and t_c=3.2 y) was 218.3 g per recruit, which indicates that the fishery is operating below the maximum Y/R at 236.9 g when t_c = 3.5 y. The Y/R was the highest at F_max and F_0.1, when t_c = 4 y (244.8 g and 214.2 g), respectively. The F_30% value was 0.85/y at t_c of 4 y with the SB/R of 338.3 g. The F_current (0.61/y at current t_c is 3.2 y) is higher than the corresponding reference points, F_0.1 (0.47/y) and F_30% (0.46/y). The ABC of kutum was estimated at 7,850 mt in 2009-2010.

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Redbud (Cercis griffithii) is an Iranian native species that plays a crucial role in protecting soil and water in Zagros forestsareas. Although many reforestation projects of this species in this area were unsuccessful, the restoration of redbud must continue using new applied studies to help conserve this precious resource. This can be achieved through increasing the quality and quantity of seedling production in nurseries. This study thus aimed to evaluate the effects of various organic amendments on growth and efficiency of redbud seedlings in a nursery. Four treatments viz.1) control (standard nursery mix) (C) 2) control: cattle manure (5:1) (CCM), 3) control: leaf composts (5:1) (CLC) and 4) control: cattle manure -leaf composts (5:1:1) (CCML)were applied for the present study. After one year, all growth indices were significantly increased by organic soil treatments compared to the standard nursery mix. Thegrowth characteristics such as height, root dry weight, length of the longest root, stem length to diameter ratio and relative height growth of redbud seedlings were associated with an organic soil treatment. These positive results on growth indices were explained by the reduction in EC and pH of planting bed induced by the organic soil amendments.

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In a completely randomized design, the effects of heavy metals of Cd, Cu, Pb and Ni at concentrations of 0, 5, 50 and 100 mg/l on chlorophyll a and biomass in green algae Scenedesmus quadricauda were investigated for 14 days under laboratory conditions of 23 °C, 12 h light: 12 hours light and light intensity of 60 mol photons/m²/s. The lowest density, chlorophyll a and dry biomass obtained at 100 mg/l in all of the heavy metals. The mean (±SE) highest increasing rates of chlorophyll a were 24.2±1.1, 23.1±0.8, 36.7±1.4 and 35.5±1.2% for Cd, Cu, Pb and Ni, respectively. Correspondingly, the reduction rates based on dry biomass were 51.5±3.1, 35.2±1.1, 47.9±1.6 and 56.6±2.8% for Cd, Cu, Ni and Pb, respectively. The results showed that heavy metals made significant reduction on chlorophyll a and dry biomass in S. quadricauda.

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Background: Adverse effects of synthetic pigments used in pharmaceutical andfoodindustriesand etc,have created a tendency toward the application of natural pigments. Environmental conditions are important factors in the growth and physiological function of different organisms. The aim of this study was to evaluate the growth rate of fungal biomass and production rate of black pigment (melanin) in fungus Exophialacrusticola under different incubation time, temperature, and light conditions to obtain an optimal condition for their production.
Materials and Methods: After obtaining an optimal incubation temperature, cultured fungus in potato dextrose agar and broth media was exposed to blue, yellow, white, red, green, and darknesslight conditions with 14-35 daysof incubation times. The averageamount of produceddry weight of fungal biomass and pigmentweremeasured, and the results were statistically analyzed with SPSS software ver.22.
Results:Suitable incubation temperature for fungal growthwas 22°C.The maximum average amount of fungal biomass (0.17 g)and pigment production (OD = 0.94) were after 35 days of incubation (p< .05) and under yellow light (0.135 g) (OD= 0.98), respectively (p< .05).
Conclusion: By optimization the incubation time, temperature, and light for the growth and production of pigmentinfungusE.crusticola, it is possible to produce a large amount of fungus and its related pigmentin order to be utilized in a variety of industrialand pharmaceutical use, and etc. Also, due to the fungus rapid growth in response to the yellow light, it is possible to use this feature in isolation and early diagnosis of this fungusin suspected pathogenesiscases.

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The production of bioethanol from lignocellulosic biomass could be considered as an appropriate and economic option to remove environmental disasters and improve energy security. In fact, lignocellulosic material is mainly composed of cellulose, hemicellulose and lignin. Lignin works as the adhering prevents the bioconversion of cellulose into sugars and ultimately to ethanol. To address the problem, various chemical, physical, physicochemical and biological methods have been suggested. Enjoying convenient operating conditions, production of non-hazardous wastes, and having no harmful side effects, make the biological methods a potentially proper option. Unfortunately, the biological methods are slower and less efficient in comparison with the other processes. In the present study, an attempt is made to resolve this problem in an enzymatic degradation of lignin of a rice straw sample. Several peroxidase enzymes were produced by a white rot fungus, and their effects on lignin removal from the biomass samples were investigated in shaking flasks. Lignin concentration and enzymes' activity were measured by the acetyl bromide-soluble lignin spectrophotometric method and optical density method using special reagents, respectively. The results revealed that the enzymatic treatment could remove at least 30% of the lignin content of the lignocellulosic biomass. To achieve the maximum activity of the enzymes, The chemical composition of the culturing medium was optimized for the concentration of important metal ions including Cu2+, Mn2+ and Zn2+ through Box Behnken response surface methodology. The enzymes' activity at the obtained optimal conditions increased four times for Manganese peroxidase, and lignin peroxidase.

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The phytoremediation capability in Pb removal from the contaminated soils by three native seedlings species (Acer cappadocicum, Fraxinus excelsior and Thuja orientalis) and one exotic species (Cupressus arizonica) were compared. The seedlings were grown in Pb contaminated soils at 0, 100, 200, 300, 400 and 500 mg kg^-1 concentrations for 6 months (Mar 21 to Sept. 22, 2015), after which the biomass allocation and Pb accumulation in tissues of root, stem, and leaf were assessed. The results showed that the higher Pb levels (400 and 500 mg kg^-1 soil) caused significant reduction in growth in all species, but this inhibition was less marked in the two conifer (T. orientalis and C. arizonica) compared to the two broad-leaf seedlings (A. cappadocicum and F. excelsior). Pb concentration in different tissues of seedlings increased with its increase in the soil. Further, Pb accumulation in the conifers was twice higher than that of the broad-leave species. Therefore, this study suggests that the two conifer species (P. orientalis and C. arizonica) can be used for phytoremediation, although further research is needed to make a final decision.

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Research subject:
As a low price biomass, rice husk is able to accumulate a large amount of silica in its texture. The process for extracting this silica is greener than the conventional ones. The present research addresses the effects of the different process parameters on amorphous silica extraction from rice husk through a precipitation method.
Research approach
In the extraction process, first the rice husk was burned in the open air and then turned into white ash in an electric furnace. This ash was converted into sodium silicate solution using NaOH, and finally the silica was precipitated from this solution by sulfuric acid. The effect of solid to solvent ratio, the duration of the alkaline dissolution step as well as the pH and temperature of acid precipitation step have been investigated. Moreover, a special application of the amorphous silica in rubber industry was also investigated.
Main results
The results showed that a low solid to solvent ratio at the alkaline dissolution stage as well as an acidic pH along with a high precipitation temperature are required to obtain the highest production efficiency and to obtain high purity amorphous silica. The purity and chemistry of obtained silica were quite similar to commercial sample in the rubber industry; however, the surface area and pore volume of obtained silica was less than the commercial one. It was also found that prolonging the alkali dissolution step slightly increases the production efficiency. The obtained silica exhibited very close performance to the commercial sample, in the rubber-to-fiber adhesion system (RFS). This indicates the high ability of precipitated silica to be replaced by commercial types, which are mainly produced by more cost-effective and less biocompatible processes.

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Background: Grazing intensity has a major effect on soil and biomass organic carbon storage (C). Various plants and ecosytems with deiffernt charactristices have their unique responses to the grazing. Recognizing the effects of grazing intensity on C in various envrionments dominated by Halocnemum strobilaceum, such as Incheboron salt land of Golestan province, helps plannig the grazing startegies.
Materials and Methods: Three grazing sites, viz. heavy grazing (in vicinity of resting point), moderate grazing (at a distance of 650 meters from resting point) and light grazing (at a distance of 2050 meters from resting point) were selceted. Sampling of soil and H. strobilaceum species was carried out with systematic-random method in Nov. 2012. In this regard, fifteen plants along the five 100 meters transects (with distance of 30m) were randomly selected and underground and abovegrond organs were extracted. The amount of biomass C was determined by combustion method. Also, soil sampling with five repetation was carried out in two depths (0-20 cm and 20-40 cm) and the amount of stored C was determined by Walkly and Black method.
Results: The sum of underground and aboveground biomass C in light grazing site was more than the heavy and moderate grazing sites, which were about 1.17, 1.07 and 0.567 ton/hectare respectively. The amount of soil C for the mentioned sites were 162.56, 137,39 and 80.76 ton/hectare, respectively. Besides, the depth 0-20 cm in all sites had a higher C. The soil C comprised more than 99 percent of ecosystem total stored C (biomas and soil C) in each site. In terms of total ecosystem C, the heavy and moderate grazing site had about 84.37 and 32.20 ton/hectare less C compred to light grazing site.
Conclusions: From a management perspective, it is concluded that light grazing intesity in saltalnd region can lead to maintenance of C in high level and grazing systems should avoid high stocking rates because it may adversely affect soil C. Heavy grazing has more negative effects on C compared to moderate grazing. Both soil and biomass respond similarly to different grazing intensities. The soil, especially first depth as the main resourcse of C, should be protected from detrioration to prevent C decling. In view point of C sequestration, it is suggested to plan grazing intesity in light level and protect the soil of rangelands.the five 100 meters transects (with distance of 30m) were selected and underground and abovegrond organs were extracted. The amount of biomass C was determined by combustion method. Also, soil sampling with five repetation was carried out on two depths (0-20 cm and 20-40 cm) and the amount of stored C was determined by Walkly and Black method. The results showed that the sum of underground and aboveground biomass C in light grazing site is more than the heavy and moderate grazing sites. This value is about 1.17, 1.07 and 0.567 ton/hectare for light, moderate and heavy grazing, respectively. The amount of soil C for the
and soil C) in each of sites.

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Aims: In relation to global climate changes, the issue of how forest ecosystems could affect biomass and soil carbon sequestration is essential.
Materials & Methods: To do this research, ailanthus (Ailanthus altissima Mill.) and Arizona cypress (Cupressus arizonica Greene) plantations were selected each one with an area of 20 hectare in forest park of Malayer, Western Iran. An adjacent area with no tree was selected as control. In each of the plantations and control area, ten plots of 20 × 20 m² deployed and biomass of trees, biodiversity indices (Shannon–Wiener, Simpson, Menhinick, and Margalef indices), and carbon sequestration of aboveground tree biomass, belowground biomass, leaf litter, grass, and soil were measured.
Findings: The results showed that the carbon sequestration in Arizona cypress plantation (32.32 t ha⁻¹) and the soil under it (11.15 t ha⁻¹) was higher than that in ailanthus plantation and the soil under it (17.99 and 7.6 t ha⁻¹, respectively). However, the soil carbon sequestration under both plantations was higher than that in control area (5.28 t ha⁻¹). According to the results, it was found that herbaceous understory of ailanthus plantation had stored carbon more than arizona cypress plantation. Furthermore, the results indicated that there is a significant difference between two plantations from the point view of the understory plant diversity (Menhinick index in ailanthus and Arizona cypress plantations was 3.17 and 2.44, respectively).
Conclusion: This research confirms that plantation with Arizona cypress tree is more efficient in soil and tree biomass carbon sequestration than plantation with ailanthus trees. Furthermore, according to the results, the understory plant richness in ailanthus plantation was higher than that in arizona cypress.

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The effects of total carbohydrate, total protein, carbohydrate/protein ratio, amino acid contents, initial pH and aeration on biomass yield product of Bacillus thuringiensis subsp. kurstaki was investigated. The bacteria were cultured in economical media comprising agricultural products and by-products including fishmeal, cottonseed meal, defatted soybean meal, cornsteep liquor, yeast extract, scotafeme, sorghum and peptone as protein sources and glucose and beet molasses as carbohydrate sources. The results indicated the presence of a direct correlation between yield biomass and carbohydrate/protein (C/N) ratio as well as the glutamic acid content of the media. The highest biomass was produced in the media providing 0.4 – 0.5 C/N ratio and 13.9% glutamic acid. A pH range of 7.0 to 8.0 was needed for high yield production. The optimal ratio for culture volume to flask size and shaking speed were 1/5 and 250 rpm, respectively. The biochemical factors described can be considered as the minimal criteria to evaluate culture media for biomass production from Bacillus thuringiensis subsp. kurstaki.

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  Emulsan compound produced by Acinetobacter calcoaceticus RAG-1 ATCC-31012. At present, this bioemulsifier show potential applications many sectors of food industry (soft cheese and ice creams). The ability of a bacterial to grow and produce emulsan by response surface methodology under shaking incubator conditions at 30°C was studied. Crude oil and ammonium sulfate at different levels use as a carbon and nitrogen source respectively. The medium culture optimum for emulsan production was occurred 4% (v/v) carbon source, 3gr/lit ammonium sulfate and 7% (v/v) inoculum’s size. At optimum levels of these parameters, 2.9 gr/lit biomass at end of fermentation was obtained. Production of emulsan by this bacterial culture resulted in surface tension reduction to 30 mN/m. Coefficients of determination, R², of fitted regression models for biomass production and surface tension are equal to 97.13% and 95.52%, respectively.

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Aims: microalgae use has been recently attracted for the production of biologically active drugs and pharmaceuticals.Carbon source is an essential factor for the Spirulina maxima growth. Since finding the appropriate carbon source and its concentration to achieve high levels of biomass in the shortest cultivation period is very valuable. Therefore, the effect of different carbon sources (sodium carbonate, sodium bicarbonate, glucose and molasses) with different concentrations (16, 24 and 32 gL^-1) on growth and biomass production were evaluated. Methods: Microalgae was grown in 11 treatments with 3 replications at labarotary temperature (28±3 °C) and 1350±100 Lux light intensity (24 hours exposure-time). Maximum specific growth rate and doubling time were calculated according to nonlinear modeling by Wolfram Mathematica software at 99% confidence interval. Findings: The highest biomass concentration (gL^-1) at the highest carbon source concentration in the first 5 days belonged to molasses (3.083), glucose (2.094), sodium carbonate (0.869) and sodium bicarbonate (0.835). Biomass production of treatments except glucose in medium was increased by increasing concentration from 16 to 32 gL^-1. Although molasses has reached on highest biomass production during the first 5 days of cultivation, but the greatest effect on increasing specific growth rate belongs to the glucose sample. Conclusions: As a result, the carbon source and its concentration had a significant effect on the growth and biomass production. Glucose has been selected as an effective carbon source for growth with a concentration of 24gL^-1. Moreover, the highest concentration of treatments had shown the least effect on specific growth rate.

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Aims: Monitoring of the fish biomass is one of the basic principal of fisheries management, but ornamental and reef fish stocks, because of difficulty of estimating their abundance, have been less studied than others. The aim of this study was to estimate the standing biomass of ornamental and reef fishes in Larak Island, in the Strait of Hormuz.
Materials &Methods: Standing biomass of the fish species was assessed seasonally using Underwater Visual Census Method (UVCm) in coral reefs and  mesophotic coral reefs in Larak Island throughout 2018 and 2019. Two popular methods in UVCm (belt transect and stationary point) were used based on topography of sea bottom. The confidence interval of estimated standing biomass is calculated using bootstrapping method.
Findings: The standing biomass of ornamental and reef fishes is estimated as 2522.18, 5222.17 and 1325.15(Kg.) in Site 1, Site 2 and Site 3, that are located in 3-15meters depth. The standing biomass at Site 4, was estimated as 884.13kg. The minimum were observed in summer, also the result showed  that the standing biomass in summer was significantly lower than other seasons (P <0.05). In addition, the temporal diagnostic test showed that population structure of fish in the spring, autumn, and winter seasons was similar but significantly different from the population structure in summer.
Conclusion: The less of standing biomass in summer season can be affected  by seasonal migrations of fish in tropical and subtropical waters to deeper waters, in order to trade of the stresses caused by temperature fluctuations.
 

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