Anthonia O’Donovan

Conversion of grass biomass into fermentable sugars and its utilization for medium chain length polyhydroxyalkanoate (mcl-PHA) production by Pseudomonas strains

This study investigated the potential of grass biomass as a feedstock for mcl-PHA production. Pretreatments (2% NaOH at 120°C or hot water at 120°C) of perennial ryegrass were employed alone or in combination with sodium chlorite/acetic acid (SC/AA) delignification to evaluate the enzymatic digestibility and subsequent utilization of resultant sugars by Pseudomonas strains. NaOH pretreated sample had better digestibility than raw and hot water treated samples and this hydrolysate supported good growth of all tested strains with limited mcl-PHA (6-17% of cell dry mass (CDM)) accumulation. Digestibility of both untreated and pretreated samples was improved after SC/AA delignification and produced glucose (74-77%) rich hydrolysates. Tested strains accumulated 20-34% of CDM as PHA when these hydrolysates were used as sole carbon and energy source. CDM and PHA yields obtained for these strains when tested with laboratory grade sugars was similar to that achieved with grass derived sugars.

Bioenergy research: An overview on technological developments and bioresources

Bioenergy is renewable energy, made through biochemical and chemical approaches, from raw materials that can be used for heat, electricity, or as liquid biofuels for transport. Bioenergy (including biofuels) and related by-/coproducts can be produced entirely from wastes such as lignocellulosic residues from forestry, agricultural, food and municipal solid wastes. In addition, bioenergy raw materials can include purpose-grown crops, virgin lignocellulosic biomass and oleaginous biomass, including algae. Renewable energy technologies, based on biological and/or chemical approaches, represent an important and rapidly growing technology sector and offer the promise for cleaner technology to reduce dependency on fossil fuels and to produce energy, commodity products and biochemicals from biomass in a sustainable manner. Biomass resources are abundant and relatively inexpensive. However, the process of growing crops and processing plants into bioenergy consumes a lot of energy and real barriers and pitfalls exist. Therefore, the factors that require consideration for sustainable and economic production are significant. For this reason much research is currently under way to develop and screen the most suitable and economically viable technological platforms as well as efficient and sustainable feedstocks to produce biofuels. This review documents current strategies and technological developments in recent biofuel research, focuses on the suitability of potential feedstocks for production of bioenergy, and outlines the main technical and socioeconomic challenges to success.

Use of a mannitol rich ensiled grass press juice (EGPJ) as a sole carbon source for polyhydroxyalkanoates (PHAs) production through high cell density cultivation

This study demonstrates the use of a mannitol rich ensiled grass press juice (EGPJ) as a renewable carbon substrate for polyhydroxyalkanoates (PHA) production in shaking flask experiments and fed-batch stirred tank reactor cultivations. Fed-batch cultivations of Burkholderia sacchari IPT101 using EGPJ as sole carbon source produced 44.5 g/L CDW containing 33% polyhydroxybutyrate (PHB) in 36 h, while Pseudomonas chlororaphis IMD555 produced a CDW of 37 g/L containing 10% of medium chain length polyhydroxyalkanoates (mcl-PHA) in 34 h. PHB and mcl-PHA extracted from B. sacchari IPT101 and P. chlororaphis IMD555, grown on EGPJ, had a molecular weight of 548 kg/mol and 115.4 kg/mol, respectively. While mcl-PHA can be produced from EGPJ, PHB production is more interesting as there is a 4-fold higher volumetric productivity compared to mcl-PHA.

Laboratory Protocols in Fungal Biology

This chapter provides basic safety information required when handling fungal cultures and when performing the procedures outlined in this manual. Several topics are discussed including routine precautions when working with fungal organisms.

Bioremediation for Fueling the Biobased Economy

Increasing CO2 emission, land degradation, and pollution are major environmental challenges that need urgent global attention. Remediation strategies are essential for tackling these issues concurrently. Here we propose integrating bioremediation with CO2 sequestration for revitalizing polluted land while deriving bioproducts from renewable and waste biomass for fueling a sustainable bioeconomy.

Acid Pre-treatment Technologies and SEM Analysis of Treated Grass Biomass in Biofuel Processing

Currently, ethanol is the most important renewable fuel in terms of volume and market value. It is produced from sugar- and starch-based materials such as sugarcane and corn, which is unsustainable. The second generation production of ethanol derived from lignocellulosic materials is now the prime target of biofuel production. Hydrolysis of lignocellulosic materials is the first step for either digestion to biogas (methane) or fermentation to ethanol. Enzymatic hydrolysis of lignocelluloses without pre-treatment is not effective because of the high stability of lignocellulose materials to enzymatic or bacterial attacks. Pre-treatment by physical, chemical or biological means are essential processes for ethanol production from lignocellulosic materials. Pre-treatment enhances the bio-digestibility of the wastes for ethanol and biogas production and increases accessibility of the enzymes to the materials. It results in enrichment of the difficult biodegradable materials, and improves the yield of ethanol or biogas. A detailed understanding of the composition of the lignocellulosic waste is essential to develop and optimize the mechanistic model for its conversion. This model primarily includes pre-treatment processes which help integrate waste streams into the raw materials for ethanol plants, for improved production of ethanol (Taherzadeh and Karimi 2008). This chapter discusses in detail the composition and chemical constituents of the grass cell wall which contributes to agricultural waste residues, a plentiful and sustainable biofuel feedstock. Pre-treatment methods are discussed with a focus on mild acid pre-treatments and scanning electron microscopy analysis (SEM) of post-treatment biomass residuals is reviewed.

Fungal Specimen Collection and Processing

The study of fungi relies, in part, on the axenic culture of isolates. Because so many fungi are found in nature in close proximity to each other, and many other organisms, study of their structure and function relies on the ability to grow and maintain a pure culture of the fungi. This chapter describes the methodology used to isolate a fungus that is present in abundance in a soil sample and covers many techniques that are widely used in microbiology laboratories.

Trichoderma in Bioenergy Research: An Overview

Abstract Development of sustainable energy systems and biomaterials based on renewable biomass feedstocks (biomass to biorefinery) is a global effort nowadays. Currently biomass is considered as the best material for bioethanol production. It is a renewable resource unlike the fossil fuels in use today. Fungi are one of the main producers of a variety of enzymes with the ability to degrade biomass, including cellulases and hemicellulases. These enzymes degrade lignocellulosic biomass to convert complex carbohydrates into simple sugars and important value added co-/by products. Trichoderma is one of the most efficient biomass-degrading fungi, and its enzymatic system is also one of the most studied. This filamentous fungus is an ideal model organism for producing a number of biomolecules along with production of many beneficial enzymes widely used in biofuels and biorefinery industries. Biotechnological applications of Trichoderma species are vast in several industries where enzymatic expression systems and production of secretary proteins are widely exploited. Thus there exists a strong demand for research on Trichoderma especially on conversion technology in bioenergy research. This chapter will present an overview on applications of Trichoderma in the bioenergy sector.Development of sustainable energy systems and biomaterials based on renewable biomass feedstocks (biomass to biorefinery) is a global effort nowadays. Currently biomass is considered as the best material for bioethanol production. It is a renewable resource unlike the fossil fuels in use today. Fungi are one of the main producers of a variety of enzymes with the ability to degrade biomass, including cellulases and hemicellulases. These enzymes degrade lignocellulosic biomass to convert complex carbohydrates into simple sugars and important value added co-/by products. Trichoderma is one of the most efficient biomass-degrading fungi, and its enzymatic system is also one of the most studied. This filamentous fungus is an ideal model organism for producing a number of biomolecules along with production of many beneficial enzymes widely used in biofuels and biorefinery industries. Biotechnological applications of Trichoderma species are vast in several industries where enzymatic expression systems and production of secretary proteins are widely exploited. Thus there exists a strong demand for research on Trichoderma especially on conversion technology in bioenergy research. This chapter will present an overview on applications of Trichoderma in the bioenergy sector.