Solid state bioconversion of oil palm empty fruit bunches for cellulase enzyme production using a rotary drum bioreactor

Synergy of Active and Passive Remote Sensing Data for Effective Mapping of Oil Palm Plantation in Malaysia

Oil palm is recognized as a golden crop, as it produces the highest oil yield among oil seed crops. Malaysia is the world’s second largest producer of palm oil; 16% of its land is planted with oil palm. To cope with the ever-increasing global demand on edible oil, additional areas of oil palm are forecast to increase globally by 12 to 19 Mha by 2050. Multisensor remote sensing plays an important role in providing relevant, timely, and accurate information that can be developed into a plantation monitoring system to optimize production and sustainability. The aim of this study was to simultaneously exploit the synthetic aperture radar ALOS PALSAR 2, a form of microwave remote sensing, in combination with visible (red) data from Landsat Thematic Mapper to obtain a holistic view of a plantation. A manipulation of the horizontal–horizontal (HH) and horizontal–vertical (HV) polarizations of ALOS PALSAR data detected oil palm trees and water bodies, while the red spectra L-band from Landsat data (optical) could effectively identify built up areas and vertical–horizontal (VH) polarization from Sentinel C-band data detected bare land. These techniques produced an oil palm area classification with overall accuracies of 98.36% and 0.78 kappa coefficient for Peninsular Malaysia. The total oil palm area in Peninsular Malaysia was estimated to be about 3.48% higher than the value reported by the Malaysian Palm Oil Board. The over estimation may be due the MPOB’s statistics that do not include unregistered small holder oil palm plantations. In this study, we were able to discriminate most of the rubber areas.

Effect of stirring on growth and cellulolytic enzymes production by Trichoderma harzianum in a novel bench-scale solid-state fermentation bioreactor

A novel bench-scale stirred bioreactor for solid-state fermentation was used to determine the effect of the stirring rate on growth and enzymes production by Trichoderma harzianum PBLA. Lab-scale static tubular bioreactors were first used to assess the effect of bioreactor diameter on heat accumulation, growth, and production of cellulases and xylanases. The increased diameters (1.8-4.2 cm) led to increases in temperature up to 36 °C (at a rate of 1.08 °C/cm), which negatively affected the growth and enzyme production. Afterward, in the bench-scale bioreactor operated at rates up to 3.0 rpm, maximum xylanases production (107 ± 0.3 U/g dm) was attained at rates of 0.5 and 1.0 rpm, reaching a maximum of 34 ± 0.3 °C. Cellulases production was reduced (up to 79%) due to stirring. Therefore, the production of xylanases by T. harzianum can be performed in this cross-flow stirred SSF bioreactor at rates up to 1.0 rpm, avoiding heat accumulation and damage on metabolic activity.

Bioreactors in solid state fermentation technology: Design, applications and engineering aspects

In recent years, substantial credibility in employing Solid-State Fermentation (SSF) technique has been witnessed owing to its numerous advantages over submerged fermentation (SmF). In spite of enormous advantages, true potential of SSF technology has not been fully realized at industrial scale. The lack of rational and scalable bioreactor designs backed by mathematical models and automated control system that could successfully address heterogeneity with respect to heat and mass, and also operate aseptically, remains the prime reason for it. As a result, there still exists vast scope in SSF bioreactor research and development to facilitate broad spectrum of biotechnological applications. The present article reviews state-of-the-art in SSF technology with focus on bioreactors that have been employed for bioprocess applications, in particular, enzyme production. Based on the mode of operation, bioreactors are divided into four categories with emphasis on design features, effect of operating conditions on productivity, applications and limitations. Selected modeling studies developed over the years, have been revised and presented in problem specific manner in order to address the limitations. Some interesting designs including few recent ones that have been proposed and/or employed at pilot and industrial levels are discussed in more detail.

Identificación y evaluación de actividad celulolítica en aislamientos nativos de Trichoderma spp obtenidos de biomasa de palma de aceite

Se aislaron previamente ocho cepas nativas de racimos de palma de aceite en descomposición de Trichoderma sp. provenientes de la región de Cumaral, Meta, Colombia. Se utilizó la región de los ITS1-ITS4 para la identificación molecular y se determinó la actividad celulolítica (actividad sobre papel filtro) del complejo producido por las cepas utilizando residuos de palma como sustrato. Siete aislamientos nativos presentarón 100% de similaridad con hongos del género Trichoderma. Se observó para siete cepas, la presencia de las cinco anclas que identifican hongos del género Trichoderma, identificándose cuatro de los hongos nativos como Trichoderma koningiopsis (HR-04-89; HR-11-89; HR-19-89; y HR-06-89) y cuatro como Trichoderma asperellum (HR-01-89; HR-03-89; HR-16-89; HR-18-89). El bioensayo mostró que las cepas evaluadas de Trichoderma son estadísticamente significativas sobre la actividad enzimática de celulasas sobre papel filtro (p<0.05). Además, las cepas HR-01-89, HR-03-89, HR-11-89, HR-04-89 y HR-18-89 no presentaron diferencias en la actividad enzimática. La cepa Trichoderma reesei utilizada como referencia, presentó un comportamiento superior y diferente comparado con las cepas nativas. La cepa nativa HR-18-89 (Trichoderma asperellum) presentó mayores niveles de actividad enzimática, 78% del valor de la cepa referencia. Es importante identificar y evaluar cepas nativas de Trichoderma sp. con novedosas actividades biológicas que permitan degradar la celulosa recalcitrante de los racimos de palma africana.

Optimization of cellulase production by Penicillium sp

The production of cellulolytic enzymes (β-exoglucanase, β-endoglucanase and β-glucosidase) by Penicillium sp. on three different media in liquid shake culture conditions was compared. The organism exhibited relatively highest activity of endoglucanase among three enzymes measured at 7-day interval during the course of its growth on Czapek-Dox medium supplemented with 0.5 % (w/v) cellulose. Cellulose at 0.5 %, lactose at 0.5 %, sawdust at 0.5 %, yeast extract at 0.2 % as a nitrogen source, pH 5.0 and 30 °C temperature were found to be optimal for growth and cellulase production by Penicillium sp. Yields of Fpase, CMCase and β-glucosidase, attained on optimized medium with Penicillium sp. were 8.7, 25 and 9.52 U/ml, respectively with increment of 9.2, 5.9 and 43.8-folds over titers of the respective enzyme on unoptimised medium. Cellulase of the fungal culture with the ratio of β-glucosidase to Fpase greater than one will hold potential for biotechnological applications.

Agricultural residues for cellulolytic enzyme production by Aspergillus niger: effects of pretreatment

Different agricultural residues were considered in this study for their ability to support cellulolytic enzyme production by Aspergillus niger. A total of eleven agricultural residues including finger millet hulls, sorghum hulls, soybean hulls, groundnut husk, banana peels, corn stalk, cassava peels, sugarcane bagasse, saw dust, rice straw and sheanut cake were subjected to three pretreatment (acid, alkali and oxidative) methods. All the residues supported the growth and production of cellulases by A. niger after 96 h of incubation. Maximum cellulase production was found in alkali-treated soybean hulls with CMCase, FPase and β-glucosidase yields of 9.91 ± 0.04, 6.20 ± 0.13 and 5.69 ± 0.29 U/g, respectively. Further studies in assessing the potential of soybean hulls are being considered to optimize the medium composition and process parameters for enhanced cellulase production.

Production and Optimization of Cellulase Enzyme Using Aspergillus niger USM AI 1 and Comparison with Trichoderma reesei via Solid State Fermentation System

Novel design solid state bioreactor, FERMSOSTAT, had been evaluated in cellulase production studies using local isolate Aspergillus niger USM AI 1 grown on sugarcane bagasse and palm kernel cake at 1 : 1 (w/w) ratio. Under optimised SSF conditions of 0.5 kg substrate; 70% (w/w) moisture content; 30°C; aeration at 4 L/h · g fermented substrate for 5 min and mixing at 0.5 rpm for 5 min, about 3.4 U/g of Filter paper activity (FPase) was obtained. At the same time, comparative studies of the enzymes production under the same SSF conditions indicated that FPase produced by A. niger USM AI 1 was about 35.3% higher compared to Trichoderma reesei. This shows that the performance of this newly designed SSF bioreactor is acceptable and potentially used as prototype for larger-scale bioreactor design.

Key technologies for bioethanol production from lignocellulose

Controversies on bioethanol produced from straw mainly revolve around the unfitted economical feasibility and environmental concerns of the process, which attribute mainly to unilateral researches from own specialties of each scholar without regard to the characteristics of the straws themselves. To achieve an economical and environmentally-friendly system of bioethanol production from straw, a number of breakthroughs are needed, not only in individual process steps, but also in the balance and combination of these processes. This article gives an overview of the new technologies required and the advances achieved in recent years, especial progresses achieved in our group, based on the concept of fractional conversions. An eco-industrial multi-production pattern is established, by which the maximum efficacy and benefit of process can be achieved due to the production of many high-value co-products simultaneously with ethanol. We believed that, in the future, the bioethanol production from straw will be competitive economically and environmentally.