The potential use of growth substrates prepared with an admixture of 10% to 75% Hudson River sediments was evaluated by analysis of changes in microbial activity (measured using Biolog Ecoplates) and ...molecular markers (presence of degradative tceA1 and bphA genes) as well as potential risks toward humans and the environment (health and environmental risk quotients). The highest microbial activity was found in growth substrate with 25% Hudson River sediments compared to unamended control soil. Significant differences were observed between samples amended with lower (0–10%) and higher (25–75%) proportion of sediment. Microbial activity increased with the proportion of sediment amendment (≥25% sediment); however, this increase in microbial activity was not affected by increasing pollutant concentrations (PCBs, Pb, Cr Ni and Zn) nor decreasing TOC content. The growth substrate amended with Hudson River sediments demonstrated a potential for PCB degradation, as evidenced by the presence of tceA1 and bphA genes responsible, respectively, for reductive dehalogenation and oxidation of a range of aromatic organic compounds including PCBs. An assessment of risk quotients showed that the growth substrates containing lower doses of Hudson River sediments (10–50%) meet the international requirements for use in agriculture/horticulture for the production of non-food crops. Nevertheless, due to the elevated content of some toxic metals and PCBs, the growth substrate prepared with the highest proportion of sediments (75%) was not suitable for agricultural/horticultural use.
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•The beneficial use of sediment-amended growth substrates was demonstrated.•The sediment dose ≥25% corresponded to higher microbial activity.•All sediment-amended growth substrates showed potential to degrade PCBs.•The substrates with ≤50% sediment can be used for production of non-food crops.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The multitude of applications to which Saccharomyces spp. are put makes these yeasts the most prolific of industrial microorganisms. This review considers biological aspects pertaining to the ...manufacture of industrial yeast biomass. It is proposed that the production of yeast biomass can be considered in two distinct but interdependent phases. Firstly, there is a cell replication phase that involves reproduction of cells by their transitions through multiple budding and metabolic cycles. Secondly, there needs to be a cell conditioning phase that enables the accrued biomass to withstand the physicochemical challenges associated with downstream processing and storage. The production of yeast biomass is not simply a case of providing sugar, nutrients, and other growth conditions to enable multiple budding cycles to occur. In the latter stages of culturing, it is important that all cells are induced to complete their current budding cycle and subsequently enter into a quiescent state engendering robustness. Both the cell replication and conditioning phases need to be optimized and considered in concert to ensure good biomass production economics, and optimum performance of industrial yeasts in food and fermentation applications. Key features of metabolism and cell biology affecting replication and conditioning of industrial Saccharomyces are presented. Alternatives for growth substrates are discussed, along with the challenges and prospects associated with defining the genetic bases of industrially important phenotypes, and the generation of new yeast strains.
"I must be cruel only to be kind: Thus bad begins, and worse remains behind." William Shakespeare: Hamlet, Act 3, Scene 4.
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BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The intensification of horticultural crops cultivation makes urgent the seeking for alternative growth substrates that could substitute non-renewable and/or synthetic growing media, such as peat and ...rock wool. The aim of the present study was to evaluate the potential use of byproducts from two industrial crops commonly cultivated in the Mediterranean basin, namely cardoon and cotton, as growth substrates for Cichorium spinosum, while zeolite addition was also tested as a soil amendment. A pot experiment was carried for two consecutive growing periods and plant growth was evaluated for six growing media compositions, while plant extracts were also evaluated in terms of their phenolic compounds profile, antioxidant and antimicrobial activities. The results of this study showed that cotton byproducts and zeolite may partially substitute peat in growth substrate of C. spinosum and high yields comparable to peat may be achieved. Phenolic compounds content and antioxidant activity of leaves' extracts was higher for plants grown in soil which showed severe stress symptoms comparing to the other tested substrate blends. Antimicrobial activity was also affected by growth substrate composition, only in the case of antibacterial properties of leaves' extracts, whereas none of the extracts presented significant antifungal activities. In conclusion, the use of cotton ginning byproducts and zeolite in growth substrate blends may partially substitute conventional substrates as peat in horticultural crops production, resulting in reduction of production cost and lessening of bulky byproducts’ management and related environmental burden without compromising yield.
•Cotton and cardoon byproducts were tested as growing media for Cichorium spinosum.•Cotton ginning byproducts showed the best results in terms of yield.•Polyphenols content and antioxidant activity were higher for soil grown plants.•Leaves' extracts showed significant activity against Enterobacter cloacae and Salmonella enterica subsp. enterica.•No antifungal activities were observed for the tested extracts.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
III‐nitrides are considered the material of choice for light‐emitting diodes (LEDs) and lasers in the visible to ultraviolet spectral range. The development is hampered by lattice and thermal ...mismatch between the nitride layers and the growth substrate leading to high dislocation densities. In order to overcome the issue, efforts have gone into selected area growth of nanowires (NWs), using their small footprint in the substrate to grow virtually dislocation‐free material. Their geometry is defined by six tall side‐facets and a pointed tip which limits the design of optoelectronic devices. Growth of dislocation‐free and atomically smooth 3D hexagonal GaN micro‐prisms with a flat, micrometer‐sized top‐surface is presented. These self‐forming structures are suitable for optical devices such as low‐loss optical cavities for high‐efficiency LEDs. The structures are made by annealing GaN NWs with a thick radial shell, reforming them into hexagonal flat‐top prisms with six equivalents either m‐ or s‐facets depending on the initial heights of the top pyramid and m‐facets of the NWs. This shape is kinetically controlled and the reformation can be explained with a phenomenological model based on Wulff construction that have been developed. It is expected that the results will inspire further research into micron‐sized III‐nitride‐based devices.
Dislocation‐free and atomically smooth 3D GaN microprisms are realized via two key epitaxial steps: growth from masked holes to eliminate threading dislocations from the substrate, followed by a crucial reformation step to achieve prisms with six parallel and equivalent side facets, with a micrometer‐sized top surface. The image shows 30° tilted‐view and side‐view SEM images of the GaN microprisms.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
La evaluación de la calidad de la semilla permite conocer el estado físico, fisiológico, genético y sanitario que presenta, así como predecir la respuesta potencial a la siembra y los primeros ...estados de crecimiento de la planta. El objetivo de la presente investigación fue evaluar el efecto de la solución nutritiva Steiner (normal y modificada) y del sustrato de crecimiento en la calidad física y fisiológica de semilla de tomate. El experimento se realizó en el invernadero del Tecnológico Nacional de México, campus Roque, ubicado en Celaya, Guanajuato, México, en el periodo marzo-julio del 2018.Se usaron dos factores: solución nutritiva Steiner completa (100 %, testigo) y dos variantes: diluida (-25 %, -50 %) y concentrada (+25 %, +50 %) y dos sustratos: tezontle rojo y fibra de coco. La cosecha (o corte) de racimos con frutos se desarrolló en cinco fechas: 72, 86, 97, 108 y 120 días después del trasplante (ddt), identificada por el color rosado/rojo del pericarpio del fruto, a partir de lo cual se determinó la calidad de la semilla extraída mediante peso de 100 semillas y porcentaje de germinación estándar. Los resultados mostraron un efecto significativo (p ≤ 0,01) de la solución nutritiva en el peso de la semilla a partir del tercer corte (97 ddt) y en la germinación estándar a 108 y 120 ddt; mientras que el sustrato lo hizo únicamente a los 97 ddt en ambas características. Así, la solución nutritiva Steiner concentrada (+25 % y +50 %) acompañada de fibra de coco promueve el mayor peso de la semilla e incrementa la germinación estándar de la semilla de tomate de 20 % a 26 %, por lo que la calidad de la semilla de tomate mejora con el manejo racional de la solución nutritiva Steiner.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Arbuscular mycorrhizal fungi (AMF) have been shown to assist plants in increasing metal tolerance and accumulation in heavy metal (HM)-contaminated soils. Herein, a greenhouse pot experiment was ...conducted to assess the interactions of growth substrates (S1, S2, and S3, respectively) with various HM contamination and nutrient status sampling from a typical contaminated soil and tailings in Shuikoushan lead/zinc mining in Hunan province, China, and AMF inoculation obtained from plants in uncontaminated areas (
,
and uninoculated, respectively) on the biomass and uptake of HMs and phosphorus (P) by the black locust plant (
L.). The results indicated that the inoculation with AMF significantly enhanced the mycorrhizal colonization of plant roots compared with the uninoculated treatments, and the colonization rates were found to be higher in S1 and S2 compared with S3, which were characterized with a higher nutrient availability and lead concentration. The biomass and heights of
were significantly increased by AMF inoculation in S1 and S2. Furthermore, AMF significantly increased the HM concentrations of the roots in S1 and S2 but decreased the HM concentrations in S3. Shoot HM concentrations varied in response to different AMF species and substrate types. Mycorrhizal colonization was found to be highly correlated with plant P concentrations and biomass in S1 and S2, but not in S3. Moreover, plant biomass was also significantly correlated with plant P concentrations in S1 and S2. Overall, these findings demonstrate the interactions of AMF inoculation and growth substrates on the phytoremediation potential of
and highlights the need to select optimal AMF isolates for their use in specific substrates for the remediation of HM-contaminated soil.
Biofilm is considered as the hotspot of antibiotic resistance gene (ARG) dissemination. Bacterial growth substrates are important factors for biofilm formation, but its spatial-temporal effects on ...ARG spread in biofilm is still unclear. In this study, microfluidics combined with microscopic observation were used to reveal spatial-temporal effects of bacterial growth substrates on ARG transfer at real time. The initial horizontal gene transfer events were found to be independent of substrate levels. However, subsequent transfer processes varied greatly depending on the availability of growth substrates. The proportion of transconjugants was much higher (~12%) when observed in substrate-rich regions (under the channel) at 24 h, followed by an exponential decline, with the distance far from the channel. Furthermore, three-dimensional observation revealed that vertical gene transfer influenced by the concentrations of bacterial growth substrates was important for ARG spread in biofilm. The transfer frequency was 8.2 times higher in the high substrate concentration (50×) compared to low concentration (0.5×) in simulated sewage, underscoring the substantial impact of bacterial growth substrate variability on ARG dissemination. This study is helpful for in-depth understanding of ARG dissemination through biofilms and indicates that reducing pollutant emission is important for ARG control in the environment.
The common bean (
Phaseolus vulgaris
L.) is the most important grain legume in the human diet with an essential role in sustainable agriculture mostly based on the symbiotic relationship established ...between this legume and rhizobia, a group of bacteria capable of fixing atmospheric nitrogen in the roots nodules. Moreover, root-associated bacteria play an important role in crop growth, yield, and quality of crop products. This is particularly true for legume crops forming symbiotic relationships with rhizobia, for fixation of atmospheric N
2
. The main objective of this work is to assess the substrate and genotype effect in the common bean (
Phaseolus vulgaris
L.) root bacterial community structure. To achieve this goal, we applied next-generation sequencing coupled with bacterial diversity analysis. The analysis of the bacterial community structures between common bean roots showed marked differences between substrate types regardless of the genotype. Also, we were able to find several phyla conforming to the bacterial community structure of the common bean roots, mainly composed by
Proteobacteria
,
Actinobacteria
,
Bacteroidetes
,
Acidobacteria
, and
Firmicutes
. Therefore, we determined that the substrate type was the main factor that influenced the bacterial community structure of the common bean roots, regardless of the genotype, following a substrate-dependent pattern. These guide us to develop efficient and sustainable strategies for crop field management based on the soil characteristics and the bacterial community that it harbors.
Raising sugarcane nurseries by single bud nodes cutting and using peat moss or coco peat as growth substrates are getting popular in many top sugarcane-producing countries worldwide. However, to ...reduce production costs, commercial growers involved in the sugarcane nursery raising business want to avoid peat moss or coco peat, which are expensive as growth substrates. We hypothesized that composted
Melia azedarach
(Chinaberry tree) sawdust can be a suitable replacement. The objective was to assess the viability, sprouting, and seedling establishment of single bud nodes of sugarcane in composted
M. azedarach
sawdust mixtures in two independent pot culture experiments. The experimental treatments were, T
1
: soil (control) (100%) (v/v), T
2
: composted sawdust of
M. azedarach
(100%) (v/v), T
3
: composted sawdust of
M. azedarach
(80%) (v/v) + composted peels of banana (20%) (v/v), T
4
: composted sawdust of
M. azedarach
(60%) (v/v) + composted peels of banana (20%) (v/v) + composted shells of eggs (20%) (v/v), and T
5
: composted sawdust of
M. azedarach
(60%) (v/v) + composted peels of banana (20%) (v/v) + composted shells of eggs (20%) (v/v) + Urea at the rate 225 kg N ha
−1
. The results exhibited that composted
M. azedarach
sawdust mixtures provoked early sprouting and triggered the growth of single bud node seedlings of sugarcane than in soil (control). The composted
M. azedarach
sawdust mixtures produced taller seedlings, more number of leaves plant
−1
, an increase in stem diameter, chlorophyll content index, leaf area, and root and shoot dry weight. It was concluded that composted
M. azedarach
sawdust mixture T
5
: composted sawdust of
M. azedarach
(60%) (v/v) + composted peels of banana (20%) (v/v) + composted shells of eggs (20%) (v/v) + Urea at the rate 225 kg N ha
−1
may be a suitable and productive alternative soilless substrate to raise single bud node seedlings of the sugarcane for nursery production.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Two IV–VI semiconductor alloys, Pb0.81Sn0.19Se and Pb0.8Sr0.2Se, are proposed for use in designing multiple quantum well (MQW) materials and devices for thermophotovoltaic (TPV) power conversion. ...These materials can be epitaxially grown on silicon substrates, so they offer the potential for a low cost TPV device manufacturing technology. MQW materials examples are provided for fabricating triple junction TPV devices for power conversion with a 1400°C radiator. Optimal n‐type and p‐type layer thicknesses for each junction were determined using internal quantum efficiency expressions derived assuming all photogenerated charge collection is by diffusion. Depending on MQW material quality and assumed optical absorption levels, predicted power generation for current matched triple junction devices ranged from 1.7 to 4.6 W/cm2 and power conversion efficiencies ranged from 15.9% to 35.7%. These device performance parameters were used in a levelized cost of energy (LCOE) calculation to predict the cost of energy provided by TPV devices with a molten silicon thermal energy storage system. Results show that even for TPV devices fabricated from low quality materials, such energy storage systems will have a low enough LCOE to be competitive with other forms of energy storage and power generation.
Two IV‐VI semiconductor alloys, PbSnSe and PbSrSe, which can be grown on silicon substrates, are proposed for use in designing multiple quantum well materials and devices for thermophotovoltaic power conversion. A power generation level of 4.6 W/cm2 and a power conversion efficiency of 35.7% are predicted for a triple junction device with a 1400°C radiator. These devices can provide cost effective power conversion from stored thermal energy
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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