High Biomass Yield Research Articles

Ethnobotany of Highland Bamboo (Arundinaria alpina (K. Schum.)) in Southern Ethiopia

Bamboo is the fastest growing plant with a relatively short rotation period and high biomass yield. However, there are little practical experience or documented traditional knowledge on how local communities manage, process and sustainably utilize bamboo resource. Therefore, the present study was aimed at: (1) assessing and documenting ethnobotanical knowledge in Chencha, Hula and Masha Districts; (2) identifying major predictor variables that influence the traditional knowledge; and (3) develop a Generalized Linear Model (GLM) to predict or explain the traditional knowledge on highland bamboo. A total of 288 informants comprising 169 men and 119 women were involved between the ages of 18 and 99. Data were collected using structured interviews, discussions and field observation. Our findings showed that 98% of the informants planted highland bamboo. The resource covered 0.93 ha (18.2%) of the total land area per household. Its harvesting contributed 17.4% cash income compared to honey (0.6%) and Eucalyptus (0.5%). Unlike Chencha and Hula Districts, bamboo shoot processing and consumption as food supplements in Masha District was a common practice. About 69% of the informants’ propagated highland bamboo using mother stock and 92.7% used cattle dung and ash. Prediction of GLM assured informants’ age and gender, time of seedling plantation and season of culms harvesting significantly (p < 0.001) influenced traditional knowledge. Lack of awareness and training and limited market access were some of the bottlenecks. Documenting traditional knowledge can serve as a basis for bamboo management, processing as well as sustainable utilization.

Towards Sustainable Bioinoculants: A Fermentation Strategy for High Cell Density Cultivation of Paraburkholderia sp. SOS3, a Plant Growth-Promoting Bacterium Isolated in Queensland, Australia

Paraburkholderia sp. SOS3 is a plant growth-promoting bacterium (PGPB) that displays pleiotropic effects and has the potential to be applied at a large scale across several agronomically important crops. The use of SOS3 is a suitable option to reduce the use of chemical fertilisers. While the benefits of SOS3 have been demonstrated in vitro, its potential applications at large scale are limited due to low biomass yield in current batch culture systems. Here, we developed a strategy for high-cell density cultivation of SOS3 in instrumented bioreactors, moving from low-biomass yield in a complex medium to high-biomass yield in a semi-defined medium. We achieved a 40-fold increase in biomass production, achieving cell densities of up to 11 g/L (OD600 = 40). This result was achieved when SOS3 was cultivated using a fed-batch strategy. Biomass productivity, initially 0.02 g/L/h in batch cultures, was improved 12-fold, reaching 0.24 g/L/h during fed-batch cultures. The biomass yield was also improved 10-fold from 0.07 to 0.71 gbiomass/gsolids. Analysis of the fermentation profile of SOS3 indicated minimal production of by-products and accumulation of polyhydroxybutyrate (PHB) during the exponential growth phase associated with nitrogen limitation in the medium. By implementing proteomics analysis in fed-batch cultures, we identified the expression of four metabolic pathways associated with growth-promoting effects, which may be used as a qualitative parameter to guarantee the efficacy of SOS3 when used as a bioinoculant. Ultimately, we confirmed that the high-cell density cultures maintained their plant growth-promoting capacity when tested in sorghum and maize under glasshouse conditions.

Effect of integrated treatment on enhancing the enzymatic hydrolysis of cocksfoot grass and the structural characteristics of co-produced hemicelluloses

BackgroundCocksfoot grass (Dactylis glomerata L.) with high biomass yield and rich cellulose can be used to produce bioethanol as fuel additive. In view of this, ultrasonic and hydrothermal pretreatments followed by successive alkali extractions were assembled into an integrated biorefinery process applied on cocksfoot grass to improve its enzymatic hydrolysis. In this work, the effects of ultrasonic and hydrothermal pretreatments followed by sequential alkali extractions on the enzymatic hydrolysis of cocksfoot grass were investigated. In addition, since large amount of hemicelluloses were released during the hydrothermal pretreatment and alkali extraction process, the yields, structural characteristics and differentials of water- and alkali-soluble hemicellulosic fractions isolated from different treatments were also comparatively explored.ResultsThe integrated treatment significantly removed amorphous hemicelluloses and lignin, resulting in increased crystallinity of the treated residues. A maximum saccharification rate of 95.1% was obtained from the cellulose-rich substrate after the integrated treatment. In addition, the considerable hemicelluloses (31.4% water-soluble hemicelluloses and 53.4% alkali-soluble hemicelluloses) were isolated during the integrated treatment. The released water-soluble hemicellulosic fractions were found to be more branched as compared with the alkali-soluble hemicellulosic fractions and all hemicellulosic fractions were mixed polysaccharides mainly composed of branched xylans and β-glucans.ConclusionThe combination of ultrasonic and hydrothermal pretreatments followed by successive alkali extractions can dramatically increase the enzymatic saccharification rate of the substrates and produce considerable amounts of hemicelluloses. Detailed information about the enzymatic hydrolysis rates of the treated substrates and the structural characteristics of the co-produced hemicelluloses will help the synergistic utilization of cellulose and hemicellulose in cocksfoot grass.

Sewage sludge amendment affects spinach yield, heavy metal bioaccumulation, and soil pollution indexes

Use of sewage sludge (SS) in crop production is a feasible strategy for its disposal; however, its application may pose an adverse impact on soil and human health. Therefore, identification of the permissible level of SS is essential to prevent soil contamination. This research not only evaluated the impact of SS application on spinach (Spinacia oleracea L.) biomass yield but also tracked the accumulation of heavy metals in soil and plants. A pot experiment was conducted on Inceptisol with different levels of SS (0, 5, 10, 15, 20, 25, 30, 35, and 40 t ha−1) with recommended dose of fertilizers (RDF). The applications of SS at 20 t ha−1 resulted in the highest biomass yield; however, the concentration of zinc (Zn) and cadmium (Cd) has exceeded the safe limit in leaves. Heavy metal accumulation in the plant was the highest in SS at 40 t ha−1. Spinach grown at 20 t ha−1 and higher dose of SS exceeded the safe limit of Zn and Cd concentration in leaves, and the translocation factor (TF) of lead (Pb) and Cd was found to be > 1. The hazard quotient (HQ) of Pb > 1 at higher doses of SS indicates health hazard if spinach is used for consumption. Assessment of health risk showed that there was a possibility of Pb hazard at a high dose of SS (HI > 1). Evaluation of various soil pollution indexes revealed that the addition of SS enhanced the buildup of Cd and chromium (Cr) in soil. This study advocated the use of SS at 10 t ha−1 to sustain soil quality with no risk of food chain contamination.

Heterotrophic and Mixotrophic Cultivation of Chlorella vulgaris using Chicken Waste Compost as Nutrients Source for Lipid Production

Microalgae have received global attention for the past decades as it shows promising results to be an alternative and sustainable energy resource due to their high growth rate and lipid production. In commercial microalgae cultivation, autotrophic method is always used to grow the microalgae. However, this method usually produces high biomass yield but low lipid content. One of the approaches to enhance the microalgae lipid yield is through heterotrophic and mixotrophic method, in which dark environment and organic carbon are introduced as a stress factor to induce the lipid productivity. In the present study, cultivations of microalgae were done using chicken compost and glucose under autotrophic, heterotrophic and mixotrophic conditions. The highest absorbance attained for both heterotrophic and mixotrophic cultivation conditions were 1.650 and 2.184 respectively when 1.0 g/L of glucose was used. Absorbance and biomass are correlated, therefore the absorbance in this study signifies the amount of biomass produced. Moreover, the highest lipid yield was successfully attained at 45 wt% under mixotrophic condition. Overall, the lipid yield of microalgae cultivated under mixotrophic was higher than the heterotrophic condition when compost derived from chicken waste was used as nutrients source.

Plant residues, beneficial microbes and integrated phosphorus management for improving hybrid maize (Zea mays L.) growth and total biomass

Phosphorus (P) unavailability and lack of organic matter in calcareous soils in semiarid climates are the major reasons for low crop productivity. This field experiment was conducted at the Agronomy Research Farm of The University of Agriculture Peshawar, during the summer of 2015 to investigate the impact of plant residues (PR) (faba bean, garlic and paper mulberry residues) and phosphorous sources [(60 and 120kg ha-1) from single super phosphate (SSP) and poultry manure (PM)] with (+) and without (-) phosphate solubilizing bacteria (PSB) on the phenological development, growth and biomass yield of hybrid maize “CS-200”. Among the PR, application of faba bean residue was found to delay phenological development (days to tasseling, silking and physiological maturity), improved growth (taller plants, higher leaf area per plant and leaf area index) and produced the highest biomass yield (faba bean&gt;garlic&gt;paper mulberry residues). Application of P at the rate of 120kg ha-1 from the inorganic source (SSP) was more beneficial in terms of better growth and higher biomass yield (120-SSP≥120-PM&gt;60-SSP&gt;60-PM kg P ha-1). The plots with (+) PSB showed enhanced phenological development, produced significantly taller plants with higher leaf area per plant and leaf area index and produced the highest biomass yield. On the basis of these results we concluded that the application of faba bean residues, phosphorus at the rate of 120kg ha-1 either from organic or inorganic sources with the inoculation of seed with PSB improved the growth and total biomass of hybrid maize in the study area.

Optimization of Medium Composition for Biomass Production of Lactobacillus plantarum 200655 Using Response Surface Methodology.

This study aimed to optimize medium composition and culture conditions for enhancing the biomass of Lactobacillus plantarum 200655 using statistical methods. The one-factor-at-a-time (OFAT) method was used to screen the six carbon sources (glucose, sucrose, maltose, fructose, lactose, and galactose) and six nitrogen sources (peptone, tryptone, soytone, yeast extract, beef extract, and malt extract). Based on the OFAT results, six factors were selected for the Plackett- Burman design (PBD) to evaluate whether the variables had significant effects on the biomass. Maltose, yeast extract, and soytone were assessed as critical factors and therefore applied to response surface methodology (RSM). The optimal medium composition by RSM was composed of 31.29 g/l maltose, 30.27 g/l yeast extract, 39.43 g/l soytone, 5 g/l sodium acetate, 2 g/l K2HPO4, 1 g/l Tween 80, 0.1 g/l MgSO4·7H2O, and 0.05 g/l MnSO4·H2O, and the maximum biomass was predicted to be 3.951 g/l. Under the optimized medium, the biomass of L. plantarum 200655 was 3.845 g/l, which was similar to the predicted value and 1.58-fold higher than that of the unoptimized medium (2.429 g/l). Furthermore, the biomass increased to 4.505 g/l under optimized cultivation conditions. For lab-scale bioreactor validation, batch fermentation was conducted with a 5-L bioreactor containing 3.5 L of optimized medium. As a result, the highest yield of biomass (5.866 g/l) was obtained after 18 h of incubation at 30°C, pH 6.5, and 200 rpm. In conclusion, mass production by L. plantarum 200655 could be enhanced to obtain higher yields than that in MRS medium.

Phenotypic plasticity of plant traits contributing to grain and biomass yield of dual-purpose sorghum.

Plant traits of interest for sorghum breeders to develop dual-purpose varieties are stem diameter, flag leaf size, crop cycle, and number of grains per panicle. To develop dual-purpose varieties, breeders need to improve traits linked both to grain and biomass production. To identify these traits, we studied the phenotypic plasticity of eighteen traits and the performance of ten contrasting sorghum genotypes, used in West Africa. Trials were carried out in a randomized complete blocks design with four replicates from 2013 to 2016 in Bambey, Sinthiou Malem and Nioro du Rip in Senegal. The results revealed three plant types. The first type, "biomass production", contained genotypes IS15401 and SK5912, and was linked to cycle duration, leaf area, and plant height. The second type, "grain production", grouped the caudatum race sorghum 621B, F2-20 and Soumba, and was associated with the number of grains per panicle and the width of the flag leaf. The third group, "dual-purpose", corresponding to the genotypes Fadda, Nieleni and Pablo, combined some favourable traits for grain and biomass: stem diameter, internode length, number of green leaves and number of grains per panicle. The study showed that high and stable grain yields were associated with stability in flag leaf size, phenology and number of grains per panicle, and a high and stable biomass yield was associated with stability in stem diameter. Those stable plant traits might be of interest for sorghum breeders selecting to develop dual-purpose varieties.

Performance of Phosphate Solubilizing Bacteria in Tea (Camellia sinensis L.) Rhizosphere

A pot experiment was conducted to assess the effect of phosphate solubilizing bacteria (PSB) on the availability of applied P in acid soil using tea (Camellia sinensis L. var. CP-1) as test crop. Six strains of PSB (Bacillus firmus strain TPB-1, Burkholderia sp. strain TPB-33, Bacillus firmus strain TPB-38, Burkholderia sp. strain TPB-40, Burkholderia cepacia strain TPB-52 and Burkholderia sp. strain TPB-57) were used for inoculation using liquid and charcoal-based delivery system. To assess the effect of PSBs on P solubilization, bacterial inocula were used with and without rock phosphate (RP) application. Results indicated that maximum P-uptake (15.6 mg/pot) in tea shoot was recorded in case of inoculation with Burkholderia sp. strain TPB-57 using charcoal-based delivery system (T12-TPB 57C). As far as the crop response is concerned, the highest biomass yield of test crop (10.5 g/pot) was also recorded with T12-TPB 57C in the presence of RP. The study indicates that as far as P solubilization by PSB in tea rhizosphere is concerned, Burkholderia sp. strain TPB-57 is an efficient microbial genus.

Ectopic overexpression of a type-II DGAT (CeDGAT2-2) derived from oil-rich tuber of Cyperus esculentus enhances accumulation of oil and oleic acid in tobacco leaves

BackgroundEngineering triacylglycerol (TAG) accumulation in vegetative tissues of non-food crops has become a promising way to meet our increasing demand for plant oils, especially the renewable production of biofuels. The most important target modified in this regard is diacylglycerol acyltransferase (DGAT) enzyme responsible for the final rate-limiting step in TAG biosynthesis. Cyperus esculentus is a unique plant largely accumulating oleic acid-enriched oil in its underground tubers. We speculated that DGAT derived from such oil-rich tubers could function more efficiently than that from oleaginous seeds in enhancing oil storage in vegetative tissues of tobacco, a high-yielding biomass crops.ResultsThree CeDGAT genes namely CeDGAT1, CeDGAT2-1 and CeDGAT2-2 were identified in C. esculentus by mining transcriptome of developing tubers. These CeDGATs were expressed in tissues tested, with CeDGAT1 highly in roots, CeDGAT2-1 abundantly in leaves, and CeDGAT2-2 predominantly in tubers. Notably, CeDGAT2-2 expression pattern was in accordance with oil dynamic accumulation during tuber development. Overexpression of CeDGAT2-2 functionally restored TAG biosynthesis in TAG-deficient yeast mutant H1246. Oleic acid level was significantly increased in CeDGAT2-2 transgenic yeast compared to the wild-type yeast and ScDGA1-expressed control under culture with and without feeding of exogenous fatty acids. Overexpressing CeDGAT2-2 in tobacco led to dramatic enhancements of leafy oil by 7.15- and 1.7-fold more compared to the wild-type control and plants expressing Arabidopsis seed-derived AtDGAT1. A substantial change in fatty acid composition was detected in leaves, with increase of oleic acid from 5.1% in the wild type to 31.33% in CeDGAT2-2-expressed tobacco and accompanied reduction of saturated fatty acids. Moreover, the elevated accumulation of oleic acid-enriched TAG in transgenic tobacco exhibited no significantly negative impact on other agronomic traits such as photosynthesis, growth rates and seed germination except for small decline of starch content.ConclusionsThe present data indicate that CeDGAT2-2 has a high enzyme activity to catalyze formation of TAG and a strong specificity for oleic acid-containing substrates, providing new insights into understanding oil biosynthesis mechanism in plant vegetative tissues. Overexpression of CeDGAT2-2 alone can significantly increase oleic acid-enriched oil accumulation in tobacco leaves without negative impact on other agronomy traits, showing CeDGAT2-2 as the desirable target gene in metabolic engineering to enrich oil and value-added lipids in high-biomass plants for commercial production of biofuel oils.

Mass collection of magnetotactic bacteria from the permanently stratified ferruginous Lake Pavin, France.

Obtaining high biomass yields of specific microorganisms for culture-independent approaches is a challenge faced by scientists studying organism's recalcitrant to laboratory conditions and culture. This difficulty is highly decreased when studying magnetotactic bacteria (MTB) since their unique behaviour allows their enrichment and purification from other microorganisms present in aquatic environments. Here, we use Lake Pavin, a permanently stratified lake in the French Massif Central, as a natural laboratory to optimize collection and concentration of MTB that thrive in the water column and sediments. A method is presented to separate MTB from highly abundant abiotic magnetic particles in the sediment of this crater lake. For the water column, different sampling approaches are compared such as in situ collection using a Niskin bottle and online pumping. By monitoring several physicochemical parameters of the water column, we identify the ecological niche where MTB live. Then, by focusing our sampling at the peak of MTB abundance, we show that the online pumping system is the most efficient for fast recovering of large volumes of water at a high spatial resolution, which is necessary considering the sharp physicochemical gradients observed in the water column. Taking advantage of aerotactic and magnetic MTB properties, we present an efficient method for MTB concentration from large volumes of water. Our methodology represents a first step for further multidisciplinary investigations of the diversity, metagenomic and ecology of MTB populations in Lake Pavin and elsewhere, as well as chemical and isotopic analyses of their magnetosomes.

ИСПОЛЬЗОВАНИЕ БИОМАССЫ НАСЕКОМЫХ ДЛЯ ВЫРАЩИВАНИЯ РАДУЖНОЙ ФОРЕЛИ В АКВАКУЛЬТУРЕ (КРАТКИЙ ОБЗОР ЗАРУБЕЖНОЙ ЛИТЕРАТУРЫ)

The article focuses on the data from foreign literature on growing rainbow trout or mykiss (Oncorhynchus mykiss) with the inclusion of dried and / or fat-free insect biomass in diets. The following seven types of insects could be recommended for inclusion in the diet of rainbow trout and other fish species: larvae and / or pupae of diptera fly (Hermetia illucens), housefly (Musca domestica), flour worm larva (Tenebrio molitor), locusts and grasshoppers (Acrididae), crickets (Gryllidae) and cathidids (Tettigoniidae), silkworm pupae (Bombyx mori). The brief data on physiology and life cycle of these insects are given, as well as the data on proteins and fatty acids concentration in fresh and dry larvae of insects. It has been shown that the flour from dried insect biomass contains a large amount of amino acids and fatty acids. There has been given the data on the influence of flour from insect larvae on the mass increase of rainbow trout juveniles and adults, digestibility of feed dry matter, organoleptic characteristics of fish fillets, amino acid and fatty acid composition, and other indicators. It has been found out that in most cases the survival rate is significantly higher in the experimental groups of Oncorhynchus mykiss juveniles fed a diet containing insect flour. It has been inferred that including flour from insect biomass in certain proportions has a positive effect on the growth and life of Oncorhynchus mykiss species. The most promising is adding Hermetia illucens larvae flour in the diet of rainbow trout in aquaculture, because Hermetia illucens larvae have the highest biomass yield per unit time compared to other insects.

Water Use Efficiency and Stress Tolerance of the Potential Energy Crop Miscanthus lutarioriparius Grown on the Loess Plateau of China.

As a potential energy crop with high biomass yield, Miscanthus lutarioriparius (M. lutarioriparius), endemic to the Long River Range in central China, needs to be investigated for its acclimation to stressful climatic and soil conditions often found on the marginal land. In this study, traits related to acclimation and yield, including survival rates, plant height (PH), stem diameter (SD), tiller number (TN), water use efficiency (WUE), and photosynthetic rates (A), were examined for 41 M. lutarioriparius populations that transplanted to the arid and cold Loess Plateau of China. The results showed that the average survival rate of M. lutarioriparius populations was only 4.16% over the first winter but the overwinter rate increased to 35.03% after the second winter, suggesting that plants having survived the first winter could have acclaimed to the low temperature. The strikingly high survival rates over the second winter were found to be 95.83% and 80.85%, respectively, for HG18 and HG39 populations. These populations might be especially valuable for the selection of energy crops for such an area. Those individuals surviving for the two consecutive winters showed significantly higher WUE than those measured after the first winter. The high WUE and low stomatal conductance (gs) observed in survived individuals could have been responsible for their acclimation to this new and harsh environment. A total of 61 individuals with productive growth traits and strong resistance to cold and drought were identified for further energy crop development. This study showed that the variation of M. lutarioriparius held great potential for developing energy crops following continuous field selection.

Lead phytoremediation potentials of four aquatic macrophytes under hydroponic cultivation

Lead (Pb) is a major toxicological concern of the present day that demands immediate attention. The use of aquatic macrophytes with high Pb tolerance and accumulation may be a very convenient and economically viable solution for remediating Pb. We examined the ability of Salvinia cucullata, Alternanthera sessilis, Lemna minor, and Pistia stratiotes to remove 0.12 mM, 0.24 mM, 0.36 mM, and 0.48 mM Pb for 96-h under hydroponic cultivation system. The plants accumulated variable amounts of Pb: S. cucullata > A. sessilis > P. stratiotes > L. minor, with low mobility of Pb from root to shoot. Lead uptake kinetics were monitored up to 96-h. After 96-h, the uptake efficiency for S. cucullata (98–99%), A. sessilis (79–96%), L. minor (45–79%), and P. stratiotes (40–76%) was noted. For S. cucullata and A. sessilis, an extremely high uptake rate was seen within the initial 24-h of trials, followed by slower uptake till 96-h. P. stratiotes and L. minor worked best at 0.12 mM Pb. Pb-Phytotoxicity became prominent at 0.48 mM exposure with biomass loss and morphological changes. The plants had a quick growth rate, extensive root system, high biomass yield, and the ability to tolerate and accumulate Pb that made them suitable for phytoremediation purposes. NOVELTY STATEMENT: Lead phytoremediation potential of four aquatic macrophytes found in Indian waters was evaluated. These macrophytes, often considered as weeds, could be used for phytoremediation purposes that would turn out to be a sustainable means of the utilization of natural resources in developing countries like India. In this study, not only metal accumulation by plants but also the lead uptake kinetics at several time intervals and valuable growth attributes were estimated to establish the suitability of these plants as probable lead phytoremediators. Two of the plant species, Salvinia cucullata, and Alternanthera sessilis, showed excellent Pb accumulation capacities that had not been reported earlier, to the best of our knowledge. The work is all the more significant as there have been needs for identifying Pb-phytoremediators well suited to native climate and growth conditions that could take up large amounts of metal from the substratum.

Physiological and transcriptional response to drought stress among bioenergy grass Miscanthus species

BackgroundMiscanthus is a commercial lignocellulosic biomass crop owing to its high biomass productivity, resilience and photosynthetic capacity at low temperature. These qualities make Miscanthus a particularly good candidate for temperate marginal land, where yields can be limited by insufficient or excessive water supply. Differences in response to water stress have been observed among Miscanthus species, which correlated to origin. In this study, we compared the physiological and molecular responses among Miscanthus species under excessive (flooded) and insufficient (drought) water supply in glasshouse conditions.ResultsA significant biomass loss was observed under drought conditions in all genotypes. M. x giganteus showed a lower reduction in biomass yield under drought conditions compared to the control than the other species. Under flooded conditions, biomass yield was as good as or better than control conditions in all species. 4389 of the 67,789 genes (6.4%) in the reference genome were differentially expressed during drought among four Miscanthus genotypes from different species. We observed the same biological processes were regulated across Miscanthus species during drought stress despite the DEGs being not similar. Upregulated differentially expressed genes were significantly involved in sucrose and starch metabolism, redox, and water and glycerol homeostasis and channel activity. Multiple copies of the starch metabolic enzymes BAM and waxy GBSS-I were strongly up-regulated in drought stress in all Miscanthus genotypes, and 12 aquaporins (PIP1, PIP2 and NIP2) were also up-regulated in drought stress across genotypes.ConclusionsDifferent phenotypic responses were observed during drought stress among Miscanthus genotypes from different species, supporting differences in genetic adaption. The low number of DEGs and higher biomass yield in flooded conditions supported Miscanthus use in flooded land. The molecular processes regulated during drought were shared among Miscanthus species and consistent with functional categories known to be critical during drought stress in model organisms. However, differences in the regulated genes, likely associated with ploidy and heterosis, highlighted the value of exploring its diversity for breeding.

Municipal Wastewater: A Sustainable Source for the Green Microalgae Chlorella vulgaris Biomass Production

The need to reduce the costs associated with microalgae cultivation encouraged scientific research into coupling this process with wastewater treatment. Thus, the aim of this work was to assess the growth of Chlorella vulgaris (Chlorophyta) in different effluents from a municipal wastewater treatment plant (WWTP), namely secondary effluent (SE) and sludge run-off (SR). Assays were performed, under the same conditions, in triplicate with 4 dilution ratios of the wastewaters (25%, 50%, 75% and 100%) with the standard culture medium bold basal medium double nitrated (BBM2N) as a control. The capability of C. vulgaris for biomass production, chlorophyll synthesis and nutrients removal in the SE and SR was evaluated. The 25% SE and 25% SR showed increased specific growth rates (0.47 and 0.55 day−1, respectively) and higher biomass yields (8.64 × 107 and 1.95 × 107 cells/mL, respectively). Regarding the chlorophyll content, the 100% SR promoted the highest concentration of this pigment (2378 µg/L). This green microalga was also able to remove 94.8% of total phosphorus of SE, while in 50% SR, 31.2% was removed. Removal of 73.9% and 65.9% of total nitrogen in 50% and 100% SR, respectively, was also observed. C. vulgaris growth can, therefore, be maximized with the addition of municipal effluents, to optimize biomass production, while cleansing the effluents.

Effects of sorghum biomass quality on ensilability and methane yield

AbstractSorghum is currently being introduced in the temperate regions of Europe. It is characterized by good digestibility and high biomass yields, which make it a useful crop for anaerobic digestion. In this study, six commercial sorghum varieties comprising four different cultivars of Sorghum bicolor L. Moench and two interspecific sorghum hybrids (Sorghum sudanense L. × S. bicolor L. Moench) were harvested on two different dates during the years 2016 and 2017 at two diverse soil‐climate sites in Germany. The fresh harvested material and silages were analyzed to examine the ensilability of the different varieties with contrasting maturity characteristics. Subsequently, methane production experiments were performed to determine the specific methane yield (SMY) of the samples. The sorghum fresh matter (FM) varied among the sorghum types, including the parameters total solids (TS; 22.69%–46.93%FM), water‐soluble carbohydrates (2.68%–11.38%TS), and nitrates (0%–0.35%TS). The excellent ensiling ability of all the sorghum types analyzed was confirmed by evaluating the fermentation profile (pH range of 3.7–4.6; dominant presence of lactic acid [LA]; acetic acid [AA] in the range of 0.70%–2.38%TS; insignificant amount of butyric acid). The SMY ranged between 231.25 and 321.31 Ln kg−1 VS and tended to decrease with the increasing harvest time and maturity. LA and AA were positively correlated with the SMY, while the neutral detergent fiber content was negatively correlated with it. The SMY—a key parameter reflecting the crop biomass quality for biogas production—was slightly higher for S. bicolor than for the sorghum hybrids. However, the results of this study confirmed that if the final purpose is biomethanation, the ensilability of different sorghum types imposes no restriction. Furthermore, different sorghum types offer a wide harvest window, which can be useful for cropping schemes, ensiling, and methane production.

Ancient wheat species are suitable to grain-only and grain plus herbage utilisations in marginal Mediterranean environments

Thanks to their low fertilization requirements and high consumer demand, ancient wheats and old durum wheat cultivars represent an attractive option for the marginal areas of Mediterranean environments no longer cultivated due to the low grain yields attainable using modern wheat cultivars. Dual-purpose utilization may increase their value in these cropping systems, but no information is available on the suitability of ancient wheat species to this type of utilization. To fill this gap, Khorasan, einkorn, and emmer wheats, clipped at the terminal spikelet stage or left unclipped, were compared in a two-year field trial. The grains were sown in the month of October, in Sardinia (41°N, 80 m asl), Italy, on low-fertility soils and with low-medium fertilization rates. Einkorn cultivars produced the highest biomass yield (2–3 t ha−1), reflecting the longer time to the onset of the terminal spikelet stage (119–138 days). After clipping, all species recovered their ability to intercept radiation to the levels of the unclipped crops, but clipping lowered their radiation use-efficiency. Grain yield was not penalized by clipping: the increase in the harvest index compensated for the decrease in biomass. Here we show for the first time that ancient wheat species are suitable for dual-purpose utilization (herbage plus grain in the same season) rendering them valuable for marginal areas; this was because the early sowing adopted for dual-purpose utilization allowed them to take full advantage of their lateness in terms of herbage yield, and to bring flowering forward (i.e. make it earlier) so that a satisfactory grain yield was obtained, even under severe water stress. Dual-purpose utilization of ancient wheats increases the sustainability of mixed cropping systems, by making herbage available to animals in a critical period, without decreasing the grain yield attainable after grazing in the same season.

Microalgal-Bacterial Consortia as Future Prospect in Wastewater Bioremediation, Environmental Management and Bioenergy Production.

In the recent years, microalgae have captured researchers' attention as the alternative feedstock for various bioenergy production such as biodiesel, biohydrogen, and bioethanol. Cultivating microalgae in wastewaters to simultaneously bioremediate the nutrient-rich wastewater and maintain a high biomass yield is a more economical and environmentally friendly approach. The incorporation of algal-bacterial interaction reveals the mutual relationship of microorganisms where algae are primary producers of organic compounds from CO2, and heterotrophic bacteria are secondary consumers decomposing the organic compounds produced from algae. This review would provide an insight on the challenges and future development of algal-bacterial consortium and its contribution in promoting a sustainable route to greener industry. It is believed that microalgal-bacterial consortia will be implemented in the near-future for sub-sequential treatment of wastewater bioremediation, bioenergy production and CO2 fixation, promoting sustainability and making extraordinary advancement in life sciences sectors.

Plasma-Activated Water as Nitrogen Source for Algal Growth: A Microcosm Study

Nitrogen is one of the most critical nutrients affecting algal cell biomass growth and thereby plays a crucial role in algal growth economics. Conventionally, all man-made nitrogen (N) sources are based on hydrogen derived from fossil fuels. This investigation examines the effect of a new N source, i.e., plasma-activated water (PAW), on yields of algal biomass. The N uptake rates of the algae for PAW were determined and it was compared with the conventional N sources. Four treatments of N source in duplicates were run to evaluate the potential of algae cultivation in batch microcosms (5 L). Mixotrophic algal cultures from a nearby eutrophied lake were incubated for 1 week with nitrate-N (NaNO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ), nitrite-N (NaNO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ), nitrate+nitrite (NaNO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> + NaNO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ), and PAW as sole N source in basal Bold's media. Even though the cultures were not axenic, steady increase in chlorophyll and biomass was observed for all the cases studied. The highest biomass yield was observed in nitrate-N fed cultures, at an average of 32.5 mg/(L·day), followed by a combination of nitrate+nitrite [27.1 mg/(L·day)], PAW-N [26.6 mg/(L·day)], and nitrite-N [22.5 mg/(L·day)] fed cultures. Nitrogen uptake rates were similar in all cultures studied. The highest rates observed were in nitrite-N [4.05 mg/(L·day)], closely followed by PAW [3.56 mg/(L·day)]. The results suggest that PAW can be utilized as a N source with pre-exposed cultures. The algal biomass yields of PAW were comparable to conventional sources although cultures with PAW showed signs of better uptake of N.