An integrated biorefinery strategy for the utilization of palm-oil wastes.

Each year, the palm oil industry generates a significant amount of biomass residue and effluent waste; both have been identified as significant sources of greenhouse gas (GHG) emissions. This issue poses a severe environmental challenge for the industry due to the possibility of long-term negative effects on human well-being. The palm-oil industry must invest significantly in the technology that is required to resolve these issues and to increase the industry's sustainability.

Metabolic Engineering of Lactobacillus plantarum for Direct l-Lactic Acid Production From Raw Corn Starch.

Fermentative production of optically pure lactic acid (LA) has attracted great interest because of the increased demand for plant-based plastics. For cost-effective LA production, an engineered Lactobacillus plantarum NCIMB 8826 strain, which enables the production of optically pure l-LA from raw starch, is constructed. The wild-type strain produces a racemic mixture of d- and l-LA from pyruvate by the action of the respective lactate dehydrogenases (LDHs).

How lipase technology contributes to evolution of biodiesel production using multiple feedstocks.

Given the increasing interest in alternative processes for producing biodiesel, we focused on the latest screening of lipases and bioprocess design using multiple feedstocks. The implementation of lipase technology to the biodiesel industry is in the early stages. However, current research has made phenomenal advances in generating lipase variants and in engineering biodiesel production.

Simultaneous conversion of free fatty acids and triglycerides to biodiesel by immobilized Aspergillus oryzae expressing Fusarium heterosporum lipase.

The presence of high levels of free fatty acids (FFA) in oil is a barrier to one-step biodiesel production. Undesirable soaps are formed during conventional chemical methods, and enzyme deactivation occurs when enzymatic methods are used. This work investigates an efficient technique to simultaneously convert a mixture of free fatty acids and triglycerides (TAG).

Production of optically pure D-lactic acid from brown rice using metabolically engineered Lactobacillus plantarum.

Simultaneous saccharification and fermentation (SSF) of D-lactic acid was performed using brown rice as both a substrate and a nutrient source. An engineered Lactobacillus plantarum NCIMB 8826 strain, in which the ʟ-lactate dehydrogenase gene was disrupted, produced 97.7 g/L D-lactic acid from 20% (w/v) brown rice without any nutrient supplementation.

Lipase cocktail for efficient conversion of oils containing phospholipids to biodiesel.

The presence of phospholipid has been a challenge in liquid enzymatic biodiesel production. Among six lipases that were screened, lipase AY had the highest hydrolysis activity and a competitive transesterification activity. However, it yielded only 21.

Enzymatic synthesis and modification of structured phospholipids: recent advances in enzyme preparation and biocatalytic processes.

Phospholipids (PLs) containing specific polar head groups and fatty acids, artificially synthesized from a complex mixture of natural PLs, have considerable industrial applications. The biocatalytic approaches to synthesizing structured PLs are of great interest because the enzymes used show high selectivity and performance under mild conditions, leading to the generation of products that cannot easily be obtained by chemical catalysis. Although the limited supply of phospholipases (e.

Production of d-lactic acid from hardwood pulp by mechanical milling followed by simultaneous saccharification and fermentation using metabolically engineered Lactobacillus plantarum.

This study focused on the process development for the d-lactic acid production from cellulosic feedstocks using the Lactobacillus plantarum mutant, genetically modified to produce optically pure d-lactic acid from both glucose and xylose. The simultaneous saccharification and fermentation (SSF) using delignified hardwood pulp (5-15% loads) resulted in the lactic acid titers of 55.2-84.

Saccharification behavior of cellulose acetate during enzymatic processing for microbial ethanol production.

This study was conducted to realize the potential application of cellulose acetate to enzymatic processing, followed by microbial ethanol fermentation. To eliminate the effect of steric hindrance of acetyl groups on the action of cellulase, cellulose acetate was subjected to deacetylation in the presence of 1N sodium hydroxide and a mixture of methanol/acetone, yielding 88.8-98.

A robust whole-cell biocatalyst that introduces a thermo- and solvent-tolerant lipase into Aspergillus oryzae cells: characterization and application to enzymatic biodiesel production.

To develop a robust whole-cell biocatalyst that works well at moderately high temperature (40-50°C) with organic solvents, a thermostable lipase from Geobacillus thermocatenulatus (BTL2) was introduced into an Aspergillus oryzae whole-cell biocatalyst. The lipase-hydrolytic activity of the immobilized A. oryzae (r-BTL) was highest at 50°C and was maintained even after an incubation of 24-h at 60°C.

An integrative process model of enzymatic biodiesel production through ethanol fermentation of brown rice followed by lipase-catalyzed ethanolysis in a water-containing system.

We attempted to integrate lipase-catalyzed ethanolysis into fermentative bioethanol production. To produce bioethanol, ethanol fermentation from brown rice was conducted using a tetraploid Saccharomyces cerevisiae expressing α-amylase and glucoamylase. The resultant ethanol was distilled and separated into three fractions with different concentrations of water and fusel alcohols.

Enzymatic biodiesel production: an overview of potential feedstocks and process development.

The increased global demand for biofuels has prompted the search for alternatives to edible oils for biodiesel production. Given the abundance and cost, waste and nonedible oils have been investigated as potential feedstocks. A recent research interest is the conversion of such feedstocks into biodiesel via enzymatic processes, which have considerable advantages over conventional alkali-catalyzed processes.

Production of biodiesel from plant oil hydrolysates using an Aspergillus oryzae whole-cell biocatalyst highly expressing Candida antarctica lipase B.

For enzymatic biodiesel production from plant oil hydrolysates, an Aspergillus oryzae whole-cell biocatalyst that expresses Candida antarctica lipase B (r-CALB) with high esterification activity was developed. Each of soybean and palm oils was hydrolyzed using Candida rugosa lipase, and the resultant hydrolysates were subjected to esterification where immobilized r-CALB was used as a catalyst. In esterification, r-CALB afforded a methyl ester content of more than 90% after 6 h with the addition of 1.

Enzymatic production of biodiesel from waste cooking oil in a packed-bed reactor: an engineering approach to separation of hydrophilic impurities.

An engineering approach was applied to an efficient biodiesel production from waste cooking oil. In this work, an enzymatic packed-bed reactor (PBR) was integrated with a glycerol-separating system and used successfully for methanolysis, yielding a methyl ester content of 94.3% and glycerol removal of 99.

Water activity dependence of performance of surface-displayed lipase in yeast cells: a unique water requirement for enzymatic synthetic reaction in organic media.

Water activity (a(w)) is a crucial parameter affecting enzymatic synthetic reactions in organic media. In this paper, we report on the a(w) dependence of surface-displayed lipases, genetically immobilized on yeast cells via fusion with cell wall proteins. When Saccharomyces cerevisiae displaying Rhizopus oryzae lipase was used for esterification in n-hexane, equilibrating the dried cells with water prior to the reaction markedly increased the reaction rate.

Process engineering and optimization of glycerol separation in a packed-bed reactor for enzymatic biodiesel production.

A process model for efficient glycerol separation during methanolysis in an enzymatic packed-bed reactor (PBR) was developed. A theoretical glycerol removal efficiency from the reaction mixture containing over 30% methyl esters was achieved at a high flow rate of 540 ml/h. To facilitate a stable operation of the PBR system, a batch reaction prior to continuous methanolysis was conducted using oils with different acid values and immobilized lipases pretreated with methyl esters.

Development of an Aspergillus oryzae whole-cell biocatalyst coexpressing triglyceride and partial glyceride lipases for biodiesel production.

An Aspergillus oryzae whole-cell biocatalyst which coexpresses Fusarium heterosporum lipase (FHL) and mono- and di-acylglycerol lipase B (mdlB) in the same cell has been developed to improve biodiesel production. By screening a number of transformants, the best strain was obtained when FHL gene was integrated into A. oryzae chromosome using sC selection marker while mdlB was integrated using niaD selection marker.

Transesterification of phosphatidylcholine in sn-1 position through direct use of lipase-producing Rhizopus oryzae cells as whole-cell biocatalyst.

The enzymatic process presents an advantage of producing specified phospholipids that rarely exist in nature. In this study, we investigated the regiospecific modification of phosphatidylcholine (PC) in the sn-1 position using immobilized Rhizopus oryzae. In a reaction mixture containing egg yolk PC and exogenous lauric acid (LA) in n-hexane, lipase-producing R.

Surfactant-modified yeast whole-cell biocatalyst displaying lipase on cell surface for enzymatic production of structured lipids in organic media.

The cell surface engineering system, in which functional proteins are genetically displayed on microbial cell surfaces, has recently become a powerful tool for applied biotechnology. Here, we report on the surfactant modification of surface-displayed lipase to improve its performance for enzymatic synthesis reactions. The lipase activities of the surfactant-modified yeast displaying Rhizopus oryzae lipase (ROL) were evaluated in both aqueous and nonaqueous systems.

Preparation and comparative characterization of immobilized Aspergillus oryzae expressing Fusarium heterosporum lipase for enzymatic biodiesel production.

In this paper, we provide the first report of utilizing recombinant fungal whole cells in enzymatic biodiesel production. Aspergillus oryzae, transformed with a heterologous lipase-encoding gene from Fusarium heterosporum, produced fully processed and active forms of recombinant F. heterosporum lipase (FHL).

Role of N-terminal 28-amino-acid region of Rhizopus oryzae lipase in directing proteins to secretory pathway of Aspergillus oryzae.

To develop a new approach for improving heterologous protein production in Aspergillus oryzae, we focused on the functional role of the N-terminal region of Rhizopus oryzae lipase (ROL). Several N-terminal deletion variants of ROL were expressed in A. oryzae.

Involvement of inducible nitric oxide synthase and receptor for advanced glycation end products in periapical granulomas.

We examined the presence of the receptor for advanced glycation end products (RAGE) in periapical granulomas and analyzed the interaction between RAGE and inducible nitric oxide synthase (iNOS) to elucidate inflammatory reaction mechanisms. Periapical lesions were surgically removed from 37 patients with chronic periapical periodontitis and halved. Paraffin sections were prepared from half of each lesion and stained with hematoxylin and eosin, whereas cryostat sections were prepared from the other half.

Development of recombinant Aspergillus oryzae whole-cell biocatalyst expressing lipase-encoding gene from Candida antarctica.

To expand the industrial applications of Candida antarctica lipase B (CALB), we developed Aspergillus oryzae whole-cell biocatalyst expressing the lipase-encoding gene from C. antarctica. A.

Lipase localization in Rhizopus oryzae cells immobilized within biomass support particles for use as whole-cell biocatalysts in biodiesel-fuel production.

To identify the lipase responsible for the methanolysis activity of fungus whole-cell biocatalysts, the lipase localization of Rhizopus oryzae cells was determined. Western blot analysis showed that R. oryzae cells produce two types of lipase with different molecular masses of 34 and 31 kDa; the former (ROL34) was bound to the cell wall, whereas the latter (ROL31) was mainly bound to the cell membrane.