Staphylococcus kloosii, an orange pigment-producing bacterium, was isolated from the respiratory tree of Holothuria (Mertensiothuria) leucospilota (Brandt 1835) from Teluk Nipah, Pangkor Island, Perak, Malaysia. This report is the first documentation of this Gram-positive strain, referred to as Strain 68 in Malaysia. A partial 16S ribosomal RNA gene sequence of the mesophilic strain has been registered with GenBank (National Center for Biotechnology Information, US National Library of Medicine) with accession number JX102547. Phylogenetic analysis using the neighbour-joining method further supported the identification of Strain 68 as S. kloosii. The circular strain produced orange pigments on tryptone glucose yeast extract agar (TGYEA) and in nutrient broth (NB) at approximately pH 7. The visible spectra of ethanolic and methanolic pigment extracts of the bacterial strain were considered identical with λmax at 426, 447 and 475 nm and λmax at 426, 445 and 473 nm, respectively. Both visible spectra resemble the visible spectra of lutein, which is a commercial carotenoid; however, further analyses are required to confirm the identity of this pigment. The methanolic extracts of the intracellular pigments comprised at least three pigment compounds: an orange pigment compound (major compound), a yellow pigment compound (the least polar) and a pink pigment compound (the most polar). These findings are the first documentation of the pigment composition of S. kloosii as no such record could be found to date.
Mango is one of the popular fruits in Malaysia and has been used in the jam, puree and drinks production. Production of food products using mango pulp has generated by-products such as peel and kernel. Disposal of these by-products will cause environmental pollution if not properly treated. Mango peel contains high nutritional composition and antioxidant properties and can be utilised as food ingredients. The objectives of this study are to determine the nutritional composition and antioxidant properties of the peels of two selected mango varieties, namely Golden Lily and Chokanan. Analysis of proximate composition, minerals, total phenolic compounds, carotenoids, and antioxidant activity (DPPH and ABTS) were carried out in this study. Results of the proximate analysis showed that the peels of both mango varieties were a good source of fibre, which were 14.45% for Golden Lily and 14.89% for Chokanan. The crude fat, crude protein, and total carbohydrate of Chokanan peel (2.62%, 4.67% and 57.74%, respectively) were higher than the Golden Lily peel (1.13%, 2.90% and 53.16%, respectively). Contrastingly, the moisture content of the Golden Lily peel (24.67%) was higher than the Chokanan peel (16.61%). Potassium was the main mineral found in both Golden Lily and Chokanan mango peels (8802.10 mg/kg and 8443.60 mg/kg, respectively). The total phenolic compounds in the peels of both mango varieties were not significantly different. The Chokanan peel contained a higher carotenoids content (35.26 µg/g) than the Golden Lily peel (15.03 µg/g). The ABTS value for Chokanan peel was higher (1406.00 μmol TE/g) than Golden Lily peel (1314.00 μmol TE/g). This study showed that Chokanan and Golden Lily mango peels have the potential to be utilised as ingredient in food products due to their high fibre content.
Carotenoids are antioxidants with pharmaceutical potential. The major carotenoids important to humans are α-carotene, β-carotene, lycopene, lutein, zeaxanthin, and β-cryptoxanthin. Some of the biological functions and actions of these individual carotenoids are quite similar to each other, whereas others are specific. Besides genotype and location, other environmental effects such as temperature, light, mineral uptake, and pH have been found affect carotenoid development in plant tissues and organs. Therefore, this research investigated the effects of the season and storage periods during postharvest handling on the accumulation of carotenoid in pumpkin. This study shows that long-term storage of pumpkins resulted in the accumulation of lutein and β-carotene with a slight decrease in zeaxanthin. The amounts of β-carotene ranged from 174.583±2.105 mg/100g to 692.871±22.019 mg/100g, lutein from 19.841±9.693 mg/100g to 59.481±1.645 mg/100g, and zeaxanthin from not detected to 2.709±0.118 mg/100g. The pumpkins were collected three times in a year; they differed in that zeaxanthin was present only in the first season, while the amounts of β-carotene and lutein were the highest in the second and third seasons, respectively. By identifying the key factors among the postharvest handling conditions that control specific carotenoid accumulations, a greater understanding of how to enhance the nutritional values of pumpkin and other crops will be gained. Postharvest storage conditions can markedly enhance and influence the levels of zeaxanthin, lutein, and β-carotene in pumpkin. This study describes how the magnitudes of these effects depend on the storage period and season.
Dendrobium Sabin Blue is an important orchid hybrid that has been grown extensively as cut flower, potted plant and is also popular for its deep purplish blue flowers. The most efficient long term conservation method of this hybrid is through cryopreservation. Cryopreservation involving the vitrification method consists of explants exposure to highly concentrated cryoprotective solution followed by freezing rapidly in liquid nitrogen. However, these treatments involved highly concentrated cryoprotectant that could incur toxicity to the explants. Hence, cryopreservation protocol requires biochemical analyses in understanding the damages or injuries occurred during cryopreservation treatments. In this study, biochemical analyses revealed a general reduction in chlorophyll, carotenoid and porphyrin content to 0.40 µg/g F W (thawing stage), 31.50 µg/g F W unloading stage and 2230.41 µg/g F W (thawing stage), respectively in comparison to the control treatments. In addition, increased level in proline content were obtained at different cryopreservation stages with highest level (5.42 µmole/g F W) recorded at the PVS2 dehydration stage. Fluctuated outcomes were obtained in catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POX) enzyme activities in PLBs exposed to different cryopreservation stages. Lowest values recorded for CAT enzyme activity were obtained at the dehydration stage (3.94 U/g). Lowest POX enzyme activities were obtained at the dehydration (122.36 U/g) and growth recovery (106.40 U/g) stages. Additionally, lowest APX enzyme activities values were recorded at the thawing (7.47 U/g) and unloading (7.28 U/g) stages. These have contributed to low regeneration of Dendrobium Sabin Blue protocorm like bodies (PLBs) following cryopreservation. Hence, in the future experimental design, exogenous antioxidant could be included in the cryopreservation procedures to improve the existing protocol.
The work entails a novel strategy of formulating the lycopene loaded whey protein isolate nanoparticles (LYC-WPI-NPs) solely using the rational blend of biomacromolecule without using equipment-intensive techniques. The LYC-WPI-NPs were fabricated as a substantial drug delivery platform, with maximum entrapment, spatial and controlled release manners, exceptional plasma concentration, and perspective for discrepancy delivery of therapeutics. Prepared nano-formulations were measured in ultra-fine size (100-350 nm) with sphere-shaped. The percent lycopene entrapment of prepared LYC-WPI-NPs was estimated in the range to 50 and 65%. In vitro percent cumulative release study demonstrated deaden and extended release i.e. approximately 75% following 16th h. The in vitro percent cell survival (cytotoxicity study) of prepared nanoparticles was evaluated against MCF-7 breast cancer cells by MTT based colorimetric assay. Sub-cellular localization of lycopene when delivered by LYC-WPI-NPs was assessed by HPLC (high performance liquid chromatography). The WPI-NPs enhance the oral bioavailability of lycopene by controlling its release from nano-formulation and facilitating its absorption through lymphatic pathways. Prophylactic anticancer efficacy of LYC-WPI-NPs was evaluated thereafter on experimentally induced breast cancer animal model. Conclusively, it may quite reasonable that lycopene loaded protein nanoparticles are competent to improve the biopharmaceutical attributes of lycopene and demonstrated prophylactic anticancer activity, decrease tumor proliferation and increase the survival rate of treated animals, thus signifying their feasible usefulness in cancer therapeutic and intervention.
Astaxanthin is one of the main carotenoid pigments. It has beneficial effects on the immune system of the human body due to its powerful antioxidant properties. The application of this bioactive compound can be found to be significant in the food, pharmaceutical, and cosmetics industries. The aim of this research was to investigate astaxanthin yield from six species of Malaysian shrimp carapace. Six types of shrimp species-Parapenaeopsis sculptili, Metapenaeus lysianassa, Macrobrachium rosenbergii, Metapenaeopsis hardwickii, Penaeus merguiensis, and Penaeus monodon-were used to investigate total carotenoid content and astaxanthin yield. The investigation was carried out using chemical extraction and high-pressure processing (HPP) methods at 210 MPa, for a period of 10 min with a solvent mixture of acetone and methanol (7:3, v/v). HPP was proven to have a significant impact in increasing the total carotenoid content and astaxanthin yield. The highest total carotenoid content and astaxanthin yield is shown to be contained in the Penaeus monodon species. Total carotenoid was increased from 46.95 µg/ml using chemical extraction to 68.26 µg/ml using HPP; yield of astaxanthin was increased from 29.44 µg/gdw using chemical extraction to 59.9744 µg/gdw using HPP. Therefore, comparison between the HPP and chemical extraction methods showed that HPP is more advantageous with higher astaxanthin yield, higher quality, and shorter extraction time.
A new effective adsorbent, 3-aminopropyltrimethoxysilane functionalized magnetic sporopollenin (MSp@SiO2NH2) based silica-coated graphene oxide (GO), (GO@SiO2-MSp@SiO2NH2) was successfully synthesized and applied for the first time in the removal of hazardous Pb(II) ions from aqueous solution. The properties of the composite were characterized using Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX) and vibrating-sample magnetometery (VSM). Evaluation of GO@SiO2-MSp@SiO2NH2 adsorption performance at optimum conditions revealed that the adsorbent has a maximum adsorption capacity of 323.5 mg/g for Pb(II) using 50-200 mg/L initial Pb(II) ions concentrations. Initial and final concentrations of Pb(II) ions in aqueous solution were analyzed using graphite furnace atomic absorption spectroscopy (GF-ASS). The adsorption behavior of Pb(II) ions onto GO@SiO2-MSp@SiO2NH2 was studied using Langmuir, Freundlich and Temkin isotherms models. The values of coefficient of determination showed that the adsorption best fitted the Langmuir model (R2 = 0.9994). Kinetic studies suggested that the adsorption of Pb(II) ion followed a pseudo-second-order rate model (R2 = 1.00) and thermodynamic studies revealed that the adsorption process is endothermic and spontaneous. The effect of co-existing ions on Pb(II) ion adsorption were also studied and found to have considerable effects only at higher matrix concentration. The adsorbent can be reused up to ten times and retain its good adsorption capacity. In addition, GO@SiO2-MSp@SiO2NH2 showed great potential for Pb(II)removal from industrial wastewater samples.
Thermal treatment is commonly applied in juice manufacturing as a method to pasteurize juices. However the heat may deteriorate some of the essential compounds in the juice, especially heat-sensitive antioxidants. Therefore non-thermal treatment such as ultraviolet (UV) ray has been proposed as an alternative for pasteurization. The objective of this study was to compare the effect of thermal and UV treatments on the content of antioxidants (phenolic acids, flavonoids, carotenoids, ascorbic acids) and antioxidant capacity of single strength pineapple juice. The antioxidants stability of juices throughout 14 days of refrigerated storage was also studied. Ultraviolet treatment shows higher ascorbic acid content after treatment as compared to thermally treated single strength pineapple juice. Storage time affected the studied antioxidants, where UV
treatment provided better stability to ascorbic acid content while thermal treatment provided better stability to flavonoids and carotenoids.
Microalgae can produce various natural products such as pigments, enzymes, unique fatty acids and vitamin that benefit humans. The objective of the study is to study the bioaccessibility of carotenoids (β-carotene and lycopene) and vitamin E (α- and β-tocopherol) of Nannochloropsis oculata and Chaetoceros calcitrans. Analyses were carried out for both the powdered forms of N. oculata and C. calcitrans, and the dried extract forms of N. oculata and C. calcitrans. In vitro digestion method together with RP-HPLC was used to determine the bioaccessibility of carotenoids and vitamin E for both forms of microalgae. Powdered form of N. oculata had the highest bioaccessibility of β-carotene (28.0 ± 0.6 g kg-1), followed by dried extract N. oculata (21.5 ± 1.1 g kg-1), dried extract C. calcitrans (16.9 ± 0.1 g kg-1), and powdered C. calcitrans (15.6 ± 0.1 g kg-1). For lycopene, dried extract of N. oculata had the highest bioaccessibility of lycopene (42.6 ± 1.1 g kg-1), followed by dried extract C. calcitrans (41.9 ± 0.6 g kg-1), powdered C. calcitrans (39.7 ± 0.1 g kg-1) and powdered N. oculata (32.6 ± 0.7 g kg-1). Dried extract C. calcitrans had the highest bioaccessibility of α-tocopherol (72.1 ± 1.2 g kg-1). However, β-tocopherol was not detected in both dried extract and powdered form of C. calcitrans. In conclusion, all samples in their dried extract forms were found to have significantly higher bioaccessibilities than their powdered forms. This may be due to the disruption of the food matrix contributing to a higher bioaccessibility of nutrients shown by the dried extract forms.
Tamarillo (Solanum betaceum Cav.) is an underutilised fruit in Malaysia. The fruit, however, contains good proportions of soluble fibre, protein, starch, anthocyanins and carotenoids. Amongst the fruits, only tamarillo mesocarp contains both polar (anthocyanins) and non-polar (carotenoids) pigments. The ability to retain both polar and non-polar pigments in the mesocarp could be related to the unique properties of its hydrocolloids. To understand the pigment-hydrocolloid interaction in the fruit, information on the physicochemical characteristics of the hydrocolloids is required. Therefore, hydrocolloids from the anthocyanin-rich seed mucilage fraction of the tamarillo and its carotenoid-rich pulp fraction were extracted and characterised. Water and 1% citric acid were used to extract the seed mucilage hydrocolloid while 72% ethanol and 20mM HEPES buffer were used for pulp hydrocolloid extraction. Seed mucilage hydrocolloid was primarily composed of arabinogalactan protein-associated pectin whereas pulp hydrocolloid was composed of hemicellulosic polysaccharides with some naturally interacting proteins and neutral polysaccharides.
In industry, the yeast Rhodotorula mucilaginosa is commonly used for the production of carotenoids. The production of carotenoids is important because they are used as natural colorants in food and some carotenoids are precursors of retinol (vitamin A). However, the identification and molecular characterization of the carotenoid pathway/s in species belonging to the genus Rhodotorula is scarce due to the lack of genomic information thus potentially impeding effective metabolic engineering of these yeast strains for improved carotenoid production. In this study, we report the isolation, identification, characterization and the whole nuclear genome and mitogenome sequence of the endophyte R. mucilaginosa RIT389 isolated from Distemonanthus benthamianus, a plant known for its anti-fungal and antibacterial properties and commonly used as chewing sticks. The assembled genome of R. mucilaginosa RIT389 is 19 Mbp in length with an estimated genomic heterozygosity of 9.29%. Whole genome phylogeny supports the species designation of strain RIT389 within the genus in addition to supporting the monophyly of the currently sequenced Rhodotorula species. Further, we report for the first time, the recovery of the complete mitochondrial genome of R. mucilaginosa using the genome skimming approach. The assembled mitogenome is at least 7,000 bases larger than that of Rhodotorula taiwanensis which is largely attributed to the presence of large intronic regions containing open reading frames coding for homing endonuclease from the LAGLIDADG and GIY-YIG families. Furthermore, genomic regions containing the key genes for carotenoid production were identified in R. mucilaginosa RIT389, revealing differences in gene synteny that may play a role in the regulation of the biotechnologically important carotenoid synthesis pathways in yeasts.
Carotenoids are a diverse group of lipid-soluble pigments that exhibit potent biological activities such as antioxidant, anti-inflammatory, and provitamin A activities. The potent health benefits of carotenoids result in the surge in the market demands for carotenoids, especially natural carotenoids from sustainable sources. Microbial carotenoids have attracted considerable interests for many industrial applications because of the low costs and ease of scaling-up with shorter production time. There is a growing interest in the search of new and sustainable microbial sources and cost-efficient production strategies following the high economical values and vast commercial applications of carotenoids. This article presents a review on the industrial production strategies of microbial carotenoids from microalgae, fungi, and bacteria sources. The industrial significance of the mass production of microbial carotenoids is also discussed. The structure, classification, and biosynthesis pathway of the carotenoids are also presented in this review.
Natural antioxidants from sustainable sources are favoured to accommodate worldwide antioxidant demand. In addition to bioprospecting for natural and sustainable antioxidant sources, this study aimed to investigate the relationship between the bioactives (i.e. carotenoid and phenolic acids) and the antioxidant capacities in fucoxanthin-producing algae. Total carotenoid, phenolic acid, fucoxanthin contents and fatty acid profile of six species of algae (five microalgae and one macroalga) were quantified followed by bioactivity evaluation using four antioxidant assays. Chaetoceros calcitrans and Isochrysis galbana displayed the highest antioxidant activity, followed by Odontella sinensis and Skeletonema costatum which showed moderate bioactivities. Phaeodactylum tricornutum and Saccharina japonica exhibited the least antioxidant activities amongst the algae species examined. Pearson correlation and multiple linear regression showed that both carotenoids and phenolic acids were significantly correlated (p<0.05) with the antioxidant activities, indicating the influence of these bioactives on the algal antioxidant capacities.
Ulam or traditional vegetables in Malaysia comprise more than 120 species representing various
families ranging from groundcovers, shrubs to trees. The leaves, shoots, flowers, fruits, roots and rhizomes of the vegetables are eaten fresh as salad or cooked and are consumed to add variety and flavor to the diet, as well as for their health benefits. Ulam species are rich in carbohydrate, protein, mineral and vitamin. This study established that ulam species differ greatly with respect to types and concentrations of carotenoids in leaves. A total of 10 species were evaluated for quantitative and qualitative carotenoid composition through spectrophotometry and HPLC analysis. The main carotenoids identified in these selected ulam were lutein, neoxanthin, violaxanthin, zeaxanthin and β-carotene. The ratio of these carotenoids varies between species.
Recognition of health benefits associated with consumption of marine derived biomasses is one of the most promising developments in human nutrition and disease-prevention research. This endeavor for bioactives and functional ingredients discovery from marine sources is “experience driven,” as such the search for therapeutically useful synthetic drugs, and functional components is like “looking for a needle in a haystack,” thus a daunting task. Zoonotic infection, adulteration, global warming and religious belief can be the star-gate barrier: - For example, the outsourcing for Glycosaminoglycans (GAGs), a pharmacologically bioactive compound have emerged as novel biomarkers and molecular players both within tumor cells and their microenvironment, as they integrate signals from growth factors, chemokines, integrins, and cell-cell matrix adhesion. As such, worldwide initiatives in outsourcing from geochemical signatures marine biomasses are flourishing. Most of these scientific interests are related to marketable compounds optimised via biotechnology applications. Approximately 50% of the US FDA approved drugs during 1981–2002 consist of either marine metabolites or their synthetic analogs. These bioactive compounds acts as antioxidant, peptides, chitoligosaccharides derivatives, sulfated polysaccharides, phlorotannins and carotenoids. Highlights from works to harness and provide scientific support to folk medicine much claimed legacy, pertaining to geochemical signatures vouchered sea cucumbers, macroalgae and crown of thorns starfish will be extrapolated.
Lycopene extraction was carried out via the ultrasonic assisted extraction (UAE) with response surface methodology (RSM). Sonication enhanced the efficiency of relative lycopene yield (enhancement of 26% extraction yield of lycopene in 6 replications at 40.0 min, 40.0 °C and 70.0% v/w in the presence of ultrasound), lowered the extraction temperature and shortened the total extraction time. The extraction was applied with the addition of oxygen-free nitrogen flow and change of water route during water bath sonication. The highest relative yield of lycopene obtained was 100% at 45.0 °C with total extraction time of 50.0 min (30:10:10) and ratio of solvent to freeze-dried tomato sample (v/w) of 80.0:1. Optimisation of the lycopene extraction had been performed, giving the average relative lycopene yield of 99% at 45.6 min, 47.6 °C and ratio of solvent to freeze-dried tomato sample (v/w) of 74.4:1. From the optimised model, the average yield of all-trans lycopene obtained was 5.11±0.27 mg/g dry weight. The all-trans lycopene obtained from the high-performance liquid chromatography (HPLC) chromatograms was 96.81±0.81% with 3.19±0.81% of cis-lycopenes. The purity of total-lycopene obtained was 98.27±0.52% with β-carotene constituted 1.73±0.52% of the extract. The current improved, UAE of lycopene from tomatoes with the aid of RSM also enhanced the extraction yield of trans-lycopene by 75.93% compared to optimised conventional method of extraction. Hence, the current, improved UAE of lycopene promotes the extraction yield of lycopene and at the same time, minimises the degradation and isomerisation of lycopene.
Although Malaysia is one of the important pineapple fruit producing and exporting country, the production of MD-2 pineapple fruit only started in 2009. Pineapple fruit has been harvested at different ripening stages for different markets. The information on Malaysian grown MD-2 pineapple fruit quality is lacking. Therefore this work was carried out with the aim to determine physicochemical quality, antioxidant compounds and activity of MD-2 pineapple fruit at five ripening stages. Ripening stage affected physicochemical quality of MD-2 pineapple fruit. Soluble solids concentration of MD-2 pineapple fruit increased from 15.41 to 18.02% SSC when fruit ripened from stage 1 to 4 and no significant difference was found in fruit between stage 4 and 5. The ascorbic acid content decreased while total carotenoids content increased as ripening stage advanced. The total phenolic content of both 80% methanol and water extraction solvents increased significantly as fruit ripened from stage 1 to 3 and reduced as fruit ripened to stage 5. The antioxidant activity of MD-2 pineapple fruit as assayed using DPPH, FRAP and ABTS showed similar trend as total phenolic content. These results suggest that ripening stage affect MD-2 pineapple fruit quality and nutritional values.
The objective of the study was to evaluate the effect of four different vegetable oils [red palm olein (RPO), palm olein (PO), corn oil (CO), coconut oil (COC)] on antioxidant enzymes activity of rat liver. Sixty six Sprague Dawley male rats which were randomly divided into eleven groups of 6 rats per group and were treated with 15% of RPO, PO, CO and COC for 4 and 8 weeks. Rats in the control group were given normal rat pellet only while in treated groups, 15% of additional different vegetable oils were given. After 4 weeks of treatment the catalase (CAT) activity results showed that there was no significance difference (p > or = 0.05) between the control group and treated groups while after 8 weeks of treatment showed that there was no significant different (p > or = 0.05) between control group and RPO group but the treated rat liver with PO, CO and COC groups were the lowest and it were significantly lower (> or = 0.05) than control group. For superoxide dismutase (SOD) there was no significance difference (p > or = 0.05) between the control group and treated groups of vegetable oils after 4 and 8 weeks of treatment. Thus the study indicated that there was no significant (p > or = 0.05) effect on antioxidant enzyme (superoxide dismutase) but there was significant effect (p > or = 0.05) on catalase in rat liver.
Microalgae are important biological resources that have a wide range of biotechnological
applications. Due to their high nutritional value, microalgae such as Spirulina and Chlorella are being mass cultured for health food. A variety of high-value products including polyunsaturated fatty acids (PUFA), pigments such as carotenoids and phycobiliproteins, and bioactive compounds are useful as nutraceuticals and pharmaceuticals, as well as for industrial applications. In terms of environmental biotechnology, microalgae are useful for bioremediation of agro-industrial wastewater, and as a biological tool for assessment and monitoring of environmental toxicants such as heavy metals, pesticides and pharmaceuticals. In recent years, microalgae have attracted much interest due to their potential use as feedstock for biodiesel production. In Malaysia, there has been active research on microalgal biotechnology for the past 30 years, tapping into the potential of our
rich microalgal resources for high-value products and applications in wastewater treatment and assessment of environmental toxicants. A culture collection of microalgae has been established, and this serves as an important resource for microalgal biotechnology
research. Microalgal biotechnology should continue to be regarded as a priority area of research in this country.
The cytosolic mevalonate (MVA) pathway in Hevea brasiliensis latex is the conventionally accepted pathway which provides isopentenyl diphosphate (IPP) for cis-polyisoprene (rubber) biosynthesis. However, the plastidic 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway may be an alternative source of IPP since its more recent discovery in plants. Quantitative RT-PCR (qRT-PCR) expression profiles of genes from both pathways in latex showed that subcellular compartmentalization of IPP for cis-polyisoprene synthesis is related to the degree of plastidic carotenoid synthesis. From this, the occurrence of two schemes of IPP partitioning and utilization within one species is proposed whereby the supply of IPP for cis-polyisoprene from the MEP pathway is related to carotenoid production in latex. Subsequently, a set of latex unique gene transcripts was sequenced and assembled and they were then mapped to IPP-requiring pathways. Up to eight such pathways, including cis-polyisoprene biosynthesis, were identified. Our findings on pre- and post-IPP metabolic routes form an important aspect of a pathway knowledge-driven approach to enhancing cis-polyisoprene biosynthesis in transgenic rubber trees.