Effect of moisture content on physical properties of animal feed pellets from pineapple plant waste

Presently, pineapple residues are recycled through open burning before replanting, thus contributed to the air pollution. One of the possible ways to manage pineapple residues is by converting them into animal feed by densification process. Densification of biomass into pellet can increase bulk density, improve storability, reduce transportation costs, and enables easier handling with proper storage equipment. The range of pellet's friability, bulk density, true density and porosity are between 0.85 - 1.22%, 303.31 - 345.24 kg m-3, 1502.65 - 1520.35 kg m-3 and 77.022 - 80.05%, respectively. Thus, from the analysis, the best condition to produce pellets from pineapple plant waste, was at 35% of moisture level

Xylitol biological production: a review of recent studies

Xylitol is an alternative sweetener that is recommended for use in food and pharmaceutical products, as it has some health benefits. It is currently produced on a large scale using a chemical reduction that requires high energy and is costly. Biological conversion of xylitol using microorganisms is an alternative process that is environmentally friendly and cost-effective. This process has been studied in an effort to provide one that is high yielding and competitive with chemical processes. This article reviews recent studies in the development of biological conversion processes for the production of xylitol, including biomass conversion, fermenting microorganisms, and new technology for full-scale process development

Preliminary study on zeolite 13X as a potential carrier for algal immobilization

Immobilization of microalgae in polymers can overcome problems associated with biomass harvesting from suspended free cells cultivated in wastewater. Although various carriers have been applied for microalgae immobilization (e.g. natural such as alginate and synthetic such as polyacrylamide), problems such as low stability, toxicity and high cost still remain a challenge for the method to be commercialized. In the present study, an effective carrier (zeolite molecular sieves 13X) has been used for the immobilization of green microalgae, Chlorella vulgaris. The immobilization was done by suspending microalgae in a culture medium with different pHs (ranging from 5-9) along with zeolite 13X. Scanning electron microscope (SEM) was used to observe the morphology of the cells adsorbed onto the carrier after the immobilization process. It was found that higher microalgal immobilization occurred in the medium with an acidic condition (pH=5) compared to other pHs. This indicates that zeolite 13X is capable to be a potential support for the immobilization of Chlorella vulgaris. Furthermore, zeolite-immobilized Chlorella can be applied in different applications such as wastewater treatment and biofuel production

Factors affecting poly(3-hydroxybutyrate) production from oil palm frond juice by Cupriavidus necator (CCUG52238(T))

Factors influencing poly(3-hydroxybutyrate) P(3HB) production by Cupriavidus necator CCUG52238(T) utilizing oil palm frond (OPF) juice were clarified in this study. Effects of initial medium pH, agitation speed, and ammonium sulfate (NH(4))(2)SO(4) concentration on the production of P(3HB) were investigated in shake flasks experiments using OPF juice as the sole carbon source. The highest P(3HB) content was recorded at pH 7.0, agitation speed of 220 rpm, and (NH(4))(2)SO(4) concentration at 0.5 g/L. By culturing the wild-type strain of C. necator under the aforementioned conditions, the cell dry weight (CDW) and P(3HB) content obtained were 9.31 ± 0.13 g/L and 45 ± 1.5 wt.%, respectively. This accounted for 40% increment of P(3HB) content compared to the nonoptimized condition. In the meanwhile, the effect of dissolved oxygen tension (DOT) on P(3HB) production was investigated in a 2-L bioreactor. Highest CDW (11.37 g/L) and P(3HB) content (44 wt.%) were achieved when DOT level was set at 30%. P(3HB) produced from OPF juice had a tensile strength of 40 MPa and elongation at break of 8% demonstrated that P(3HB) produced from renewable and cheap carbon source is comparable to those produced from commercial substrate

Residual palm oil recovery from empty fruit bunches and palm oil mill effluent

Oil extraction rate (OER) is a universal indicator to measure the actual amount of oil obtained from the oil palm fresh fruit bunches (OPFFB) at palm oil mills. The maximum OER from a ripe oil palm fresh fruit bunch was estimated to be 30%. Over the past few decades, the OER has not made significant improvement and the reasons always being associated with soil, climate, oil palm species and age, poor milling operation and machine inefficiency. Not many efforts have been given to determine the oil loss in the palm oil wastes and wastewater as well as to recover it. The proof is over the years, the palm oil industry has not changed much in terms of its processing and design. Most of the process and machinery design in the mill are still using the same technology since 50 years ago. Therefore, there is an urgent need to provide a re-engineering solution for some of the processing especially to recover and reuse the residual oil. Palm oil mill effluent (POME) and oil palm empty fruit bunch (OPEFB) are main by-products generated from milling process, which contain high amount of residual oil. For instance, about 0.6 – 0.7 % residual oil was found in POME and about 15 – 28 % (dried weight basis) was found on OPEFB spikelet. High pressure water spray system and micro/nano-bubble system are eco-friendly combination method that can be employed to remove oil from OPEFB and separate oil from aqueous solution (oil-water obtained from OPEFB and POME), respectively. The aim of this research work is to evaluate the recovery and utilizing residual crude palm oil from waste streams of palm oil milling process for the production of any value added product (e.g. biodiesel)

Transformation of cyclodextrin glucanotransferase (CGTase) from aqueous suspension to fine solid particles via electrospraying

In this study, the potential of electrohydrodynamic atomization or electrospraying to produce nanometer-order CGTase particles from aqueous suspension was demonstrated. CGTase enzyme was prepared in acetate buffer solution (1% v/v), followed by electrospraying in stable Taylor cone-jet mode. The deposits were collected on aluminium foil (collector) at variable distances from the tip of spraying needle, ranging from 10 to 25 cm. The Coulomb fission that occurs during electrospraying process successfully transformed the enzyme to the solid state without any functional group deterioration. The functional group verification was conducted by FTIR analysis. Comparison between the deposit and the as-received enzyme in dry state indicates almost identical spectra. By increasing the distance of the collector from the needle tip, the average particle size of the solidified enzyme was reduced from 200 ± 117 nm to 75 ± 34 nm. The average particle sizes produced from the droplet fission were in agreement with the scaling law models. Enzyme activity analysis showed that the enzyme retained its initial activity after the electrospraying process. The enzyme particles collected at the longest distance (25 cm) demonstrated the highest enzyme activity, which indicates that the activity was controlled by the enzyme particle size

Bleached kenaf microfiber as a support matrix for cyclodextrin glucanotransferase immobilization via covalent binding by different coupling agents

Enzyme immobilization via covalent binding provides a strong interaction between enzyme and support material. In this study, the effect of different coupling agents (spacer arms and ligands) in cyclodextrin glucanotransferase (CGTase) immobilization on bleached kenaf microfiber as a support matrix was investigated. The immobilized CGTase properties such as storage stability, thermal stability and reusability were evaluated. Immobilized CGTases on microfiber resulted in 0.162–0.24 U/mg-fiber when 55.6 U/mL of CGTase activity was initially added during the immobilization. The highest storage stability (60 °C) was shown by CGTase that was immobilized with ethylenediamine and o-phthalaldehyde, whereby 60% of its activity remained after 15 days. Its high stability was also confirmed by the lowest deactivation constant, kd that was obtained at 25 °C (0.0161 day−1) and 60 °C (0.0361 day−1). The CGTase immobilized using ethylenediamine and glutaraldehyde has shown the best retention of enzyme activity up to 72.72% after 12 cycles of batch reaction. The results indicate that kenaf microfiber has potential to be applied as a support for enzyme immobilization and its enzymatic properties were affected by the coupling agents

Stability improvement of algal-alginate beads by zeolite molecular sieves 13X

This research aimed to improve the stability of Chlorella-Alginate Beads (CABs) by zeolite molecular sieves 13X. Dissolution time of synthesized Zeolite-Algal-Alginate Beads (ZABs) in a chelating agent revealed a significant improvement on the beads stability (78.5 ± 0.5 min) compared to the control beads (51.5 ± 0.5 min) under the optimum conditions of zeolite/alginate (1.5:1), pH 5 and 2% of beads. Monitoring cell growth during 5 days of incubation showed good biocompatibility of zeolite 13X. Scanning electron microscopy (SEM) indicated rough surface and spherical shapes of ZABs. Energy dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FTIR) of ZABs confirmed the presence of zeolite 13X within the matrix. The zeta potential value of ZABs indicated that the beads were relatively stable. The findings of this research showed that zeolite molecular sieves 13X have the potential to improve the stability of algal-alginate beads compared to common beads

Development of coconut-based floating structure for stand-alone solar PV system in the tropics

The use of plastics and composite materials as the base structure for a floating solar photovoltaic system commonly known as floatovoltaic system can cause negative impact to the environment especially the aquatic life and human. Additive materials are infused to form the plastics by which giving adverse effect to our metabolism. Despite the fact that the plastics are durable, to create and recycle it will produce toxic materials of many kinds in addition to the higher expenses for floatovoltaic installation. The unique approach of floatovoltaic is further discussed withstanding the continuous constraint of limited and suitable land for solar PV farms. This paper presents field analysis of the development of coconut-trunk as the base structure for a floatovoltaic system with regards to the environmental impact. A framework based on the density and buoyancy of the coconut trunk material is considered for the desig

Periodic addition of anaerobic sludge enhanced the lignocellulosic degradation rate during co-composting of oil palm biomass

The main objective of this work was to investigate the effects of the controlled periodic addition of anaerobic sludge during composting to increase amount of microbial DNA, which appears to be correlated to soluble sugar content which may relate to rate of lignocellulosic degradation. In this study, the composting of pressed-shredded oil palm empty fruit bunch with the periodic addition of palm oil mill effluent anaerobic sludge for moisture control in a newly designed in-vessel type composter was carried out. A control experiment was also conducted over the same period but with the periodic addition of water for moisture control instead of the anaerobic sludge. The lignocellulosic composition and the reducing sugar content were determined via fibre analysis and the spectrophotometric method respectively. The bacterial profile throughout the composting process was quantified by using qPCR. The growth of bacteria reached its peak at 48°C and the degradation of lignocellulose was highest during the thermophilic stage. The highest content of reducing sugar coincided with the highest degradation rate of lignocellulose and the highest DNA copy number during the thermophilic stage. Under the controlled experimental condition of increasing the microbial community, the composting was accelerated to 2.07% OM degradation per day compared to the water addition control at 0.60% OM per day