Publications by authors named "Jean S VanderGheynst"

Soil biosolarization (SBS) is an alternative technique for soil pest control to standard techniques such as soil fumigation and soil solarization (SS). By using both solar heating and fermentation of organic amendments, faster and more effective control of soilborne pathogens can be achieved. A circular economy may be created by using the residues of a given crop as organic amendments to biosolarize fields that produce that crop, which is termed circular soil biosolarization (CSBS).

View Article and Find Full Text PDF

Global demand for poultry and associated feed are projected to double over the next 30 years. Insect meal is a sustainable alternative to traditional feeds when produced on low-value high-volume agricultural byproducts. Black soldier fly (BSF) larvae (Hermetia illucens L.

View Article and Find Full Text PDF

The properties of digestates generated through anaerobic digestion are influenced by interactions between the digester microbial communities, feedstock properties and digester operating conditions. This study investigated the effect of varying initial feedstock carbon to nitrogen (C/N) ratios on digestate microbiota and predicted abundance of genes encoding lignocellulolytic activity. The C/N ratio had a significant impact on the digestate microbiome.

View Article and Find Full Text PDF

Background: Insect biomass is a sustainable alternative to traditional animal feeds, particularly when insects are produced on low-value high-volume agricultural by-products. Seven samples of almond by-product (hulls and shells) were obtained from processors in California and investigated for larvae production. Experiments were completed with and without larvae and spent substrate samples were assessed for their potential as soil amendments based on standard compost quality indicators.

View Article and Find Full Text PDF

Regulatory pressure along with environmental and human health concerns drive the development of soil fumigation alternatives such as soil biosolarization (SBS). SBS involves tarping soil that is at field capacity with a transparent film following amendment with certain organic materials. Heating via the greenhouse effect results in an increase of the soil temperature.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the use of microalgae, specifically Chlorella sorokiniana, for treating wastewater and producing biofuels.
  • Microalgae biomass production varied significantly, with concentrations between 0.14 g/L and 0.90 g/L, while nutrient removal efficiencies for total nitrogen, ammonium nitrogen, and chemical oxygen demand ranged from 34% to 97%.
  • The research found that the microbial community, particularly the genus Pusillimonas, positively correlates with biomass production and nutrient removal during microalgae cultivation in wastewater.
View Article and Find Full Text PDF
Article Synopsis
  • Biosolarization involves using organic materials to create natural pesticides in the soil to help eliminate agricultural pests.
  • Researchers studied almond processing by-products, specifically hulls and hull-shell mixtures, to see how effective they were in enhancing biosolarization.
  • The findings revealed that these almond by-products not only increased the production of beneficial organic acids in the soil but also led to significant mortality rates of root lesion nematodes when sufficient biomass was used.
View Article and Find Full Text PDF
Article Synopsis
  • Wastewater treatment is energy-intensive and produces greenhouse gases, largely from the aeration process needed for bacteria to break down organic materials.
  • Algae can provide excess dissolved oxygen, potentially reducing the need for mechanical aeration in these processes.
  • A study tested the effectiveness of algae (Auxenochlorella protothecoides) in speeding up the breakdown of organic compounds by bacteria (E. coli), finding that algae presence accelerated removal rates by 18-66% and helped offset one-third of the biochemical oxygen demand.
View Article and Find Full Text PDF

Increases in global human population are leading to increasing demands for food production and waste management. Insect biomass is a sustainable alternative to traditional animal feeds when insects are produced on lignocellulosic by-products. Resources high in lignocellulose have high carbon to nitrogen ratios and require nitrogen supplementation to accelerate bioconversion.

View Article and Find Full Text PDF

Background: The increasing production of almonds worldwide has resulted in the significant generation of byproduct streams that require end uses. One potential use for byproducts is for cultivation of additional food sources including insects. Studies were performed to determine if black soldier fly larvae (Hermetia illucens L.

View Article and Find Full Text PDF

The management of organic wastes is an environmental and social priority. Aerobic digestion (AED) or composting and anaerobic digestion (AD) are two organic waste management practices that produce a value-added final product. Few side-by-side comparisons of both technologies and their digestate products have been performed.

View Article and Find Full Text PDF
Article Synopsis
  • The study compared traditional solarization to biosolarization using mature compost and tomato processing waste to see how these methods affected pest control and tomato plant growth in soil.
  • It measured soil oxygen depletion and volatile fatty acid accumulation in biosolarized soils, observing variations by soil depth and across two years of experiments.
  • Results indicated that when volatile fatty acids were present after biosolarization, tomato yield was similar to solarization; however, without these acids, biosolarized plants produced significantly more vegetation and fruit.
View Article and Find Full Text PDF

Transgene introgression is a major concern associated with transgenic plant-based vaccines. Agroinfiltration can be used to selectively transform nonreproductive organs and avoid introgression. Here, we introduce a new vaccine modality in which Staphylococcal enterotoxin B (SEB) genes are agroinfiltrated into radishes ( L.

View Article and Find Full Text PDF
Article Synopsis
  • Soil biosolarization may be a beneficial alternative to traditional fumigation, utilizing volatile fatty acids (VFAs) from fermented organic matter to help control pests like Brassica nigra (BN) and Fusarium oxysporum (FOL).
  • While BN seed mortality was slightly higher in biosolarized soil compared to solarized soil, the correlation between VFA levels and BN mortality suggests that VFAs play a role in pest management.
  • The study indicates that the method of organic waste stabilization affects the effectiveness of biosolarization, highlighting the potential for improved pest control and enhanced soil quality through better organic waste practices.
View Article and Find Full Text PDF

Anaerobic digestion is an organic waste bioconversion process that produces biofuel and digestates. Digestates have potential to be applied as soil amendment to improve properties for crop production including phytonutrient content and pest load. Our objective was to assess the impact of solid anaerobic digestates on weed seed inactivation and soil quality upon soil biosolarization (a pest control technique that combines solar heating and amendment-induced microbial activity).

View Article and Find Full Text PDF

Ionic liquid (IL) pretreatment is a promising approach for the conversion of lignocellulose to biofuels. The toxicity of residual IL, however, negatively impacts the performance of industrial enzymes and microorganisms in hydrolysis and fermentation. In this study, a thermophilic microbial community was cultured on switchgrass amended with various levels of the ionic liquid 1-ethyl-3-methylimidazolium acetate.

View Article and Find Full Text PDF

Chemical and physical pretreatment of biomass is a critical step in the conversion of lignocellulose to biofuels and bioproducts. Ionic liquid (IL) pretreatment has attracted significant attention due to the unique ability of certain ILs to solubilize some or all components of the plant cell wall. However, these ILs inhibit not only the enzyme activities but also the growth and productivity of microorganisms used in downstream hydrolysis and fermentation processes.

View Article and Find Full Text PDF

Background: Biosolarization is a fumigation alternative that combines passive solar heating with amendment-driven soil microbial activity to temporarily create antagonistic soil conditions, such as elevated temperature and acidity, that can inactivate weed seeds and other pest propagules. The aim of this study was to use a mesocosm-based field trial to assess soil heating, pH, volatile fatty acid accumulation and weed seed inactivation during biosolarization.

Results: Biosolarization for 8 days using 2% mature green waste compost and 2 or 5% tomato processing residues in the soil resulted in accumulation of volatile fatty acids in the soil, particularly acetic acid, and >95% inactivation of Brassica nigra and Solanum nigrum seeds.

View Article and Find Full Text PDF

The aims of this study were to identify thermophilic microbial communities that degrade green waste in the presence of the ionic liquids (IL) tetrabutylphosphonium chloride and tributylethylphosphonium diethylphosphate and examine preservation methods for IL-tolerant communities. High-solids incubations with stepwise increases in IL concentration were conducted to enrich for thermophilic IL-tolerant communities that decomposed green waste. 16S rRNA sequencing of enriched communities revealed microorganisms capable of tolerating high levels of IL.

View Article and Find Full Text PDF

Background: Microbial communities enriched from diverse environments have shown considerable promise for the targeted discovery of microorganisms and enzymes for bioconversion of lignocellulose to liquid fuels. While preservation of microbial communities is important for commercialization and research, few studies have examined storage conditions ideal for preservation. The goal of this study was to evaluate the impact of preservation method on composition of microbial communities enriched on switchgrass before and after storage.

View Article and Find Full Text PDF

Pomaces from tomato paste and wine production are the most abundant fruit processing residues in California. These residues were examined as soil amendments for solarization to promote conditions conducive to soil disinfestation (biosolarization). Simulated biosolarization studies were performed in both aerobic and anaerobic soil environments and soil temperature elevation, pH, and evolution of CO2, H2 and CH4 gases were measured as metrics of soil microbial activity.

View Article and Find Full Text PDF

Water-in-oil emulsions containing silica nanoparticles (Aerosil R974) have the potential to stabilize microalgae for long-term storage. Studies were completed to determine if smectite clays could be used as an alternative to Aerosil R974. Emulsions were prepared with Aerosil R974, and hectorite and bentonite clays in the continuous phase and Chlorella sorokiniana was added to the aqueous phase to monitor the effects of solid particles on emulsion stability.

View Article and Find Full Text PDF

Lipid productivity and fatty acid composition are important metrics for the production of high quality biodiesel from algae. Our previous results showed that co-culturing the green alga Chlorella minutissima with Escherichia coli under high-substrate mixotrophic conditions enhanced both culture growth and crude lipid content. To investigate further, we analyzed neutral lipid content and fatty acid content and composition of axenic cultures and co-cultures produced under autotrophic and mixotrophic conditions.

View Article and Find Full Text PDF

Microalgae have been proposed as a potential feedstock for biofuel production; however, cell disruption is usually required for collection and utilization of cytoplasmic polysaccharides and lipids. Virus infection might be one approach to disrupt the cell wall. The concentration of yeast extract and presence of KNO3 in algae cultivation media were investigated to observe their effects on Chlorella variabilis NC64A physiology and composition and the subsequent effect on production of Chlorella virus and disruption of infected cells.

View Article and Find Full Text PDF
Article Synopsis
  • New lignocellulolytic enzymes are needed for industrial biomass deconstruction due to harsh conditions like high temperatures and lack of water, making enriched microbial communities a potential source for these enzymes.
  • The study sequenced metatranscriptomes from microbial communities in compost, focusing on those enriched on rice straw under different temperature conditions to identify which enzymes were overexpressed in thermophilic settings.
  • Key enzymes identified belonged to specific protein families and were predominantly linked to a single bacterial genus, Micromonospora, highlighting the potential for new, unrepresented genes for biomass deconstruction.
View Article and Find Full Text PDF