Cell mass production of Acinetobacter calcoaceticus in palm oil-limited chemostat culture

Chemostat culture of Acinetobacter calcoaceticus KB-2 was done under palm oil-limiting conditions for cell production, and variation of cell compositions and yield coefficients were investigated in connection with the specific growth rates. At the concentration of 0.6% palm oil, the productivity of cells and yield coefficient were 4.76 g cells/l/h and 1.18 g cells/g palm oil, respectively, at a practical dilution rate of 0.85 h⁻¹. About 80% of the palm oil was assimilated by the strain, and the maintenance coefficient was 0.035 g palm oil/g cells/h. Although the carbohydrate content remained essentially constant when the growth rate was varied, the lipid, protein, and nucleic acid contents were increased slightly at higher growth rates. Although the protein content increased only 3%, the protein yield coefficient (Y_p) increased about 1.5 times over the range of specific growth rates between 0.1 and 0.7 h⁻¹. The increase in Y_p was due to the higher protein content of the biomass and to higher values of the cell yield coefficient.     

Growth of the oleaginous microalga Aurantiochytrium sp. KRS101 on cellulosic biomass and the production of lipids containing high levels of docosahexaenoic acid

We examined the growth of a novel oleaginous microalga, Aurantiochytrium sp. KRS101, using cellulosic materials as nutrients, and the resultant production of lipids containing high levels of docosahexaenoic acid (DHA). The microalgal strain could grow using either carboxymethylcellulose or cellobiose as a carbon source, and produced lipids containing high levels of DHA (49-58% of total fatty acids). In line with this growth behavior, carboxymethylcellulase and cellobiohydrolase activities were evident in both cell-free lysates and culture broths. Additionally, an industrial cellulosic biomass, palm oil empty fruit bunches (POEFB), a by-product of the palm oil industry, were utilized by the microalgal strain for cell growth and lipid production.     

The incorporation of [1-14C]acetate into lipids during embryogenesis in oil palm tissue cultures

A tissue culture line of oil palm produced embryoids and during the embryogenesis large quantities of lipid were stored in the cells. The synthesis of the lipid was monitored by measuring incorporation of[1-¹⁴C]acetate, under optimum conditions, into the total lipid and separation by TLC into neutral and polar lipid. Both synthesis of triacylglycerol and polar lipid increased during embryoid formation. A rapid increase in the formation of polar lipid occurred in the period just before the embryoids became visible and this probably corresponded with the increased rate of cell division that occurred at that time.     

European renewable energy directive: Critical analysis of important default values and methods for calculating greenhouse gas (GHG) emissions of palm oil biodiesel

Purpose

The aim of this paper is to evaluate assumptions and data used in calculations  related to palm oil produced for biodiesel production relative to the European Renewable Energy Directive (EU-RED). The intent of this paper is not to review all assumptions and data, but rather to evaluate whether the methodology is applied in a consistent way and whether current default values address relevant management practices of palm oil production systems.

Methods

The GHG calculation method provided in Annex V of the EU-RED was used to calculate the GHG-emissions from palm oil production systems. Moreover, the internal nitrogen recycling on the plantation was calculated based on monitoring data in North Sumatra.

Results and discussion

A calculation methodology is detailed in Annex V of the EU-RED. Some important aspects necessary to calculate the GHG emission savings correctly are insufficiently considered, e.g.: ? “Nitrogen recycling” within the plantation due to fronds remaining on the plantation is ignored. The associated organic N-input to the plantation and the resulting nitrous oxide emissions is not considered within the calculations, despite crop residues being taken into account for annual crops in the BIOGRACE tool. ? The calculation of GHG-emissions from residue and waste water treatment is inappropriately implemented despite being a hot-spot for GHG emissions within the life cycle of palm oil and palm oil biodiesel. Additionally, no distinction is made between palm oil and palm kernel oil even though palm kernel oil is rarely used for biodiesel production. ? The allocation procedure does not address the most relevant oil mill management practices. Palm oil mills produce crude palm oil (CPO) in addition either nuts or palm kernels and nut shells. In the first case, the nuts would be treated as co-products and upstream emissions would be allocated based on the energy content; in the second case the kernels would be treated as co-products while the shelöls are considered as waste without upstream emissions. This has a significant impact on the resulst or GHG savings, respectively. ? It is not specified whether indirect GHG emissions from nitrogen oxide emission from the heat and power unit of palm oil mills should be taken into account.

Conclusions and recommendations

In conclusion, the existing calculation methodology described in Annex V of the EU-RED and default values are insufficient for calculating the real GHG emission savings from palm oil and palm oil biodiesel. The current default values do not reflect relevant management practices. Additionally, they protect poor management practices, such as the disposal of empty fruit bunches (EFB), and lead to an overestimation of GHG savings from palm oil biodiesel. A default value for EFB disposal must be introduced because resulting GHG emissions are substantial. Organic nitrogen from fronds must be taken into account when calculating real GHG savings from palm oil biodiesel. Further, more conservative data for FFB yield and fugitive emissions from wastewater treatment should be introduced in order to foster environmental friendly management options. Moreover, credits for bioenergy production from crop residues should be allowed in order to foster the mobilization of currently unused biomass.     

Renewable and sustainable bioenergies production from palm oil mill effluent (POME): win-win strategies toward better environmental protection

Palm oil industry is one of the leading agricultural industries in Malaysia with average crude palm oil production of more than 13 million tonne per year. However, production of such huge amount of crude palm oil has consequently resulted to even larger amount of palm oil mill effluent (POME). POME is a highly polluting wastewater with high chemical oxygen demand (COD) and biochemical oxygen demand (BOD) in which can caused severe pollution to the environment, typically pollution to water resources. On the other hand, POME was identified as a potential source to generate renewable bioenergies such as biomethane and biohydrogen through anaerobic digestion. In other words, a combination of wastewater treatment and renewable bioenergies production would be an added advantage to the palm oil industry. In line with the world's focus on sustainability concept, such strategy should be implemented immediately to ensure palm oil is produced in an environmental friendly and sustainable manner. This review aims to discuss various technologies to convert POME to biomethane and biohydrogen in a commercial scale. Furthermore, discussion on using POME to culture microalgae for biodiesel and bioethanol production was included in the present paper as a new remedy to utilize POME with a greater beneficial return.     

Rapid growth of a thermotolerant yeast on palm oil

A thermotolerant and rapidly-growing yeast for production of single cell protein from palm oil was isolated and identified as Candida tropicalis F129. The optimum temperature and pH for growth were 38°C and 6.0, respectively. The yeast grew with a high specific growth rate, of 0.92/h in 2% (v/v) palm oil medium, compared with other oil-assimilating yeasts or hydrocarbon-utilizing thermophilic yeasts. The overall cell yield was 1.01 g dry cells/g palm oil after 12 h.     

Morphological and transcript changes in the biosynthesis of lignin in oil palm (Elaeis guineensis) during Ganoderma boninense infections in vitro

Lignification of the plant cell wall could serve as the first line of defense against pathogen attack, but the molecular mechanisms of virulence and disease between oil palm and Ganoderma boninense are poorly understood. This study presents the biochemical, histochemical, enzymology and gene expression evidences of enhanced lignin biosynthesis in young oil palm as a response to G. boninense (GBLS strain). Comparative studies with control (T1), wounded (T2) and infected (T3) oil palm plantlets showed significant accumulation of total lignin content and monolignol derivatives (syringaldehyde and vanillin). These derivatives were deposited on the epidermal cell wall of infected plants. Moreover, substantial differences were detected in the activities of enzyme and relative expressions of genes encoding phenylalanine ammonia lyase (EC 4.3.1.24), cinnamate 4‐hydroxylase (EC 1.14.13.11), caffeic acid O‐methyltransferase (EC 2.1.1.68) and cinnamyl alcohol dehydrogenase (CAD, EC 1.1.1.195). These enzymes are key intermediates dedicated to the biosynthesis of lignin monomers, the guaicyl (G), syringyl (S) and ρ‐hydroxyphenyl (H) subunits. Results confirmed an early, biphasic and transient positive induction of all gene intermediates, except for CAD enzyme activities. These differences were visualized by anatomical and metabolic changes in the profile of lignin in the oil palm plantlets such as low G lignin, indicating a potential mechanism for enhanced susceptibility toward G. boninense infection.     

饲料中棕榈油替代鱼油和豆油对黄颡鱼生长和肌肉脂肪酸组成的影响

为研究不同棕榈油替代水平对黄颡鱼生长性能、肌肉脂肪酸组成、形体指标和肝脏组织结构的影响, 实验采用5组等氮(400 g/kg)等脂(100 g/kg)等能(15.70 MJ/kg)饲料饲喂黄颡鱼[(16.15±0.04) g], 对照饲料以鱼油鲶豆油1鲶2混合为脂肪源, 实验饲料以棕榈油分别替代10、25、40和55 g/kg的混合脂肪源。经过8周的养殖实验, 结果表明棕榈油替代水平对黄颡鱼的摄食量、终末体重、特定生长率、饲料效率和蛋白沉积率未产生显著性的影响(P>0.05), 但是上述指标均呈现先升高后略微下降的趋势, 并在25 g/kg替代组达到最大值。背肌肌肉中亚油酸和n-3HUFA含量随着棕榈油替代水平的上升而显著下降(P<0.05), 但n-3/n-6比值随着棕榈油替代水平的上升而显著上升(P<0.05), 棕榈油替代水平对各组黄颡鱼的肥满度和脏体比未产生显著性的影响(P>0.05), 但是55 g/kg棕榈油替代水平组肝体比显著高于25 g/kg棕榈油添加组(P<0.05), 且55 g/kg棕榈油替代水平组黄颡鱼的肝脏组织出现细胞肿胀, 细胞核移位, 肝血窦和脂肪细胞数量明显增多等不良影响。据上所述: 对于黄颡鱼幼鱼, 棕榈油可以替代25 g/kg的混合脂肪源(鱼油鲶豆油=1鲶2)不影响鱼体生长性能并且在一定程度上改善了背肌肌肉脂肪酸组成。     

Selection of lipase producing yeasts for methanol-tolerant biocatalyst as whole cell application for palm-oil transesterification

Methanol-tolerant lipase producing yeast was successfully isolated and selected thorough ecological screening using palm oil-rhodamine B agar as one step-approach. All 49 lipase-producing yeasts exhibited the ability to catalyze esterification reaction of oleic acid and methanol at 3 molar equivalents. However, only 16 isolates catalyzed transesterification reaction of refined palm oil and methanol. Rhodotorula mucilagenosa P11I89 isolated from oil contaminated soil showed the strongest hydrolytic lipase activity of 1.2U/ml against palm oil. The production of oleic methyl ester and fatty acid methyl ester (FAME) of 64.123 and 51.260% was obtained from esterification and transesterification reaction catalyzed by whole cell of R. mucilagenosa P11I89 in the presence of methanol at 3 molar equivalents against the substrates, respectively. FAME content increased dramatically to 83.29% when 6 molar equivalents of methanol were added. Application of the methanol-tolerant-lipase producing yeast as a whole cell biocatalyst was effectively resolved major technical obstacles in term of enzyme stability and high cost of lipase, leading to the feasibility of green biodiesel industrialization.     

不同时间下低温胁迫对油棕幼苗生理生化变化的影响

为了研究不同时间的低温胁迫对油棕幼苗生理生化变化的影响,以8个月苗龄的油棕幼苗为材料,根据海南的气温变化规律,设置4个不同的最低温度处理,分别为28℃(CK处理),18℃（T1处理）、12℃（T2处理）、6℃（T3处理）,分别处理0、7、14、21 d时取样。结果发现,随着温度的下降和低温胁迫时间的延长,幼苗叶片含水量、SOD活性不断下降;可溶性蛋白、可溶性糖含量、H₂O₂、MDA含量不断升高;POD、CAT、APX活性先上升而后下降;T2、T3处理2周后的幼苗其心叶都变褐色,且生长明显减缓。低温会对油棕幼苗造成了明显地氧化伤害,但油棕幼苗可能通过提高可溶性蛋白、可溶性糖等物质的含量,抗氧化酶维持一定活性的适应机制,以抵抗低温造成的氧化伤害,维持其正常生长。     

Switching from monoculture to polyculture farming benefits birds in oil palm production landscapes: Evidence from mist netting data

Monoculture farming is pervasive in industrial oil palm agriculture, including those RSPO plantations certified as sustainably managed. This farming practice does not promote the maintenance of farmland biodiversity. However, little scientific attention has been given to polyculture farming in oil palm production landscapes. Polyculture farming is likely to increase the floristic diversity and stand structural complexity that underpins biodiversity. Mist nets were used to sample birds at 120 smallholdings in Peninsular Malaysia. At each site, 12 vegetation structure characteristics were measured. We compared bird species richness, abundance, and composition between monoculture and polyculture smallholdings and used predictive models to examine the effects of habitat quality on avian biodiversity. Bird species richness was significantly greater in polyculture than that of monoculture smallholdings. The number of fallen and standing, dead oil palms were also important positive predictors of species richness. Bird abundance was also strongly increased by standing and dead oil palms and decreased with oil palm stand height. Our results indicate that polyculture farming can improve bird species richness in oil palm production landscapes. In addition, key habitat variables that are closely associated with farming practices, such as the removal of dead trees, should and can be managed by oil palm growers in order to promote biodiversity. To increase the sustainability of oil palm agriculture, it is imperative that stakeholders modify the way oil palms are currently planted and managed. Our findings can guide policy makers and certification bodies to promote oil palm production landscapes that will function more sustainably and increase existing biodiversity of oil palm landscapes.     

The impact of tropical forest logging and oil palm agriculture on the soil microbiome

Selective logging and forest conversion to oil palm agriculture are rapidly altering tropical forests. However, functional responses of the soil microbiome to these land‐use changes are poorly understood. Using 16S rRNA gene and shotgun metagenomic sequencing, we compared composition and functional attributes of soil biota between unlogged, once‐logged and twice‐logged rainforest, and areas converted to oil palm plantations in Sabah, Borneo. Although there was no significant effect of logging history, we found a significant difference between the taxonomic and functional composition of both primary and logged forests and oil palm. Oil palm had greater abundances of genes associated with DNA, RNA, protein metabolism and other core metabolic functions, but conversely, lower abundance of genes associated with secondary metabolism and cell–cell interactions, indicating less importance of antagonism or mutualism in the more oligotrophic oil palm environment. Overall, these results show a striking difference in taxonomic composition and functional gene diversity of soil microorganisms between oil palm and forest, but no significant difference between primary forest and forest areas with differing logging history. This reinforces the view that logged forest retains most features and functions of the original soil community. However, networks based on strong correlations between taxonomy and functions showed that network complexity is unexpectedly increased due to both logging and oil palm agriculture, which suggests a pervasive effect of both land‐use changes on the interaction of soil microbes.     

The effects of palm oil breakdown products on lipid turnover and morphology of fungi

The oleaginous fungi Cryptococcus curvatus and Mucor circinelloides were used to determine the effect of palm oil breakdown products, measured as polymerized triglycerides (PTGs), on lipid turnover and on fungal growth and morphology. In M. circinelloides, we found after 7 days of growth, a decrease in biomass and in lipid utilization and accumulation at increased PTG levels, both at low and neutral pH. In C.?curvatus, there was also a decrease in lipid utilization and biomass production at increased PTG levels, at both low and neutral pH. However, an increase in oil accumulation was observed at low pH while it remained similar at neutral pH for all PTG levels tested. Hairy and warty protuberances on the cell surface were observed when C. curvatus was grown on oils with 15% and 45% PTGs, respectively. Using nano scanning Auger microscopy, we found no evidence to suggest a difference in elemental composition of the surfaces of the warty protuberances compared with the rest of the cell wall surface. We conclude that the warty protuberances are outgrowths of cell walls and that the changes observed in lipid turnover in both fungi are due to the presence of palm oil breakdown products.     

Effects of land use on surface-atmosphere exchanges of trace gases and energy in Borneo: comparing fluxes over oil palm plantations and a rainforest

This paper reports measurements of land-atmosphere fluxes of sensible and latent heat, momentum, CO(2), volatile organic compounds (VOCs), NO, NO(2), N(2)O and O(3) over a 30 m high rainforest canopy and a 12 m high oil palm plantation in the same region of Sabah in Borneo between April and July 2008. The daytime maximum CO(2) flux to the two canopies differs by approximately a factor of 2, 1200 mg C m(-2) h(-1) for the oil palm and 700 mg C m(-2) h(-1) for the rainforest, with the oil palm plantation showing a substantially greater quantum efficiency. Total VOC emissions are also larger over the oil palm than over the rainforest by a factor of 3. Emissions of isoprene from the oil palm canopy represented 80 per cent of the VOC emissions and exceeded those over the rainforest in similar light and temperature conditions by on average a factor of 5. Substantial emissions of estragole (1-allyl-4-methoxybenzene) from the oil palm plantation were detected and no trace of this VOC was detected in or above the rainforest. Deposition velocities for O(3) to the rainforest were a factor of 2 larger than over oil palm. Emissions of nitrous oxide were larger from the soils of the oil palm plantation than from the soils of the rainforest by approximately 25 per cent. It is clear from the measurements that the large change in the species composition generated by replacing rainforest with oil palm leads to profound changes in the net exchange of most of the trace gases measured, and thus on the chemical composition of the boundary layer over these surfaces.     

Changes in photosynthetic activity in five common hybrids of oil palm (Elaeis guineensis Jacq.) seedlings under water deficit

The leaf water potential, gas-exchange parameters and chlorophyll fluorescence were evaluated in five common oil palm (Elaeis guineensis Jacq.) tenera hybrids 913X1988, 1425X2277, 748X1988, 7418X1988, and 690X1988 under water deficit with an aim to identify hybrids which can cope up better under such conditions and understand possible differences among hybrids in relation to the physiological mechanisms triggered by water deficit. Our findings indicate oil palm hybrids 913X1988, 1425X2277, and 7418X1988 maintained higher leaf water potentials than the other hybrids. Hybrids 7418X1988 and 1425X2277 recorded lower stomatal conductance after water deficit, which resulted in higher intrinsic water-use efficiency. The excess light energy produced due to decreased photosynthesis in 7418X1988 and 690X1988 hybrids under water deficit was dissipated as heat by higher nonphotochemical quenching. The maximum efficiency of photosystem II was not affected, even after withholding water for 24 days, suggesting an increased efficiency of photoprotection mechanisms in all these oil palm hybrids.     

Dietary fat composition modifies the effect of boron on bone characteristics and plasma lipids in rats

Female and male rats weighing about 170 g and 200 g, respectively, were fed diets (approximately 70 microg boron/kg) in a factorial arrangement with supplemental boron at 0 (deficient) and 3 (adequate) mg/kg and canola oil or palm oil at 75 g/kg of diet as variables. After 5 weeks, six females in each treatment were bred. Dams and pups continued on their respective dietary treatments through gestation, lactation and post-weaning. Thirteen weeks after weaning, plasma and bones were collected from 12 male and 12 female offspring in each treatment. Boron supplementation increased femur strength measured by the breaking variable bending moment; tibial calcium and phosphorus concentrations; and plasma alkaline phosphatase. Femur breaking stress was greatest in boron-supplemented rats fed canola oil, and lowest in boron-deprived females fed canola oil; this group also exhibited the lowest femur bending moment. Minerals associated with bone organic matrix, zinc and potassium, were increased by boron supplementation in tibia. Plasma phospholipids were decreased by boron deprivation in females, but not males. Plasma cholesterol was decreased in boron-supplemented males by replacing canola oil with palm oil. The findings suggest that a diet high in omega-3 alpha-linolenic acid promotes femur strength best when the dietary boron is adequate.     

Conservation Value and Permeability of Neotropical Oil Palm Landscapes for Orchid Bees

The proliferation of oil palm plantations has led to dramatic changes in tropical landscapes across the globe. However, relatively little is known about the effects of oil palm expansion on biodiversity, especially in key ecosystem-service providing organisms like pollinators. Rapid land use change is exacerbated by limited knowledge of the mechanisms causing biodiversity decline in the tropics, particularly those involving landscape features. We examined these mechanisms by undertaking a survey of orchid bees, a well-known group of Neotropical pollinators, across forest and oil palm plantations in Costa Rica. We used chemical baits to survey the community in four regions: continuous forest sites, oil palm sites immediately adjacent to forest, oil palm sites 2km from forest, and oil palm sites greater than 5km from forest. We found that although orchid bees are present in all environments, orchid bee communities diverged across the gradient, and community richness, abundance, and similarity to forest declined as distance from forest increased. In addition, mean phylogenetic distance of the orchid bee community declined and was more clustered in oil palm. Community traits also differed with individuals in oil palm having shorter average tongue length and larger average geographic range size than those in the forest. Our results indicate two key features about Neotropical landscapes that contain oil palm: 1) oil palm is selectively permeable to orchid bees and 2) orchid bee communities in oil palm have distinct phylogenetic and trait structure compared to communities in forest. These results suggest that conservation and management efforts in oil palm-cultivating regions should focus on landscape features.     

Rapid and Dense Culture of Acinetobacter calcoaceticus on Palm Oil

A soil microorganism, identified as Acinetobacter calcoaceticus KB-2, was cultivated on palm oil as a carbon source for cell production. This organism grew with a specific growth rate of l.lOh^?1. The pH optimum for growth was between 6.5 and 7.0, and the temperature optimum was 39°C. Compared with other strains on water-insoluble substrates such as hydrocarbons and natural oils and fats so far reported, the cultivation time for this strain was short and the cell mass productivity was relatively high. More than 90% of the palm oil was assimilated by this strain, and the overall cell yield was 1.02 (g of cells/g of palm oil) after 8 hr cultivation with the concentration of 3% palm oil.