Wax Lipids from Leaf Surfaces of Some Common plants of Malaysia

Epicuticular wax lipids from leaves of some common plant species found in the Klang Valley, Malaysia were extracted into dichloromethane for analysis. Extracts were separated into hydrocarbon, carboxylic acid, ketone and alcohol fractions. The fractions after derivatization were then subjected to gas chromatographic (GC) and gas chromatography-mass spectrometric (GC-M5) analyses. The wax yield was highest for Mestta ferrea while the lowest yield was obtained from Eugenia gran dis. In most species studied the m~or n-alkane was found to be hentriacontane (C31 ), followed by tritriacontane (C,,) and nonacosane (C",) , respectively. The n-alkanes exhibit a saw-tooth pattern which is characteristic of a biogenic origin. A strong even-to-odd carbon number predominance is observed for both the n-alkanoic acids and 1)alkanols. Only traces of mainly B-sitosterol were detected in some of the species. The triterpenoids and triterpenes were mostly found in the wax of Mesua ferrea with «- and p-boswellic acids as the major components and minor amounts of «- and p-amyrin. Other biomarkers identified were «and p-amyrones, friedelin, friedelanol, friedelane, olean-12-ene, taraxerene, squalene, dihydronyctanthic acid, dihydroroburic acid and dihydrocanaric acid. This study has shown that the distribution of n-alkanes is a function of the ambient temperature

Environmental factors controlling the distributions of Botryococcus braunii (A, B and L) biomarkers in a subtropical freshwater wetland

Here we report the molecular biomarker co-occurrence of three different races of Botryococcus braunii (B. braunii) in the freshwater wetland ecosystem of the Florida Everglades, USA. Thespecific biomarkers include C32–C34 botryococcenes for race B, C27–C32 n-alkadienes and n-alkatrienes for race A, and lycopadiene for race L. The n-alkadienes and n-alkatrienes were present up to 3.1 and 69.5 µg/g dry weight (dw), while lycopadiene was detected in lower amounts up to 3.0 and 1.5 µg/g dw in periphyton and floc samples, respectively. Nutrient concentrations (P and N) did not significantly correlate with the abundances of these compounds. In contrast, n-alkadienes and n-alkatrienes were present in wider diversity and higher abundance in the floc from slough (deeper water and longer hydroperiod) than ridge (shallower water and shorter hydroperiod) locations. n-Alkadienes, n-alkatrienes, and lycopadiene, showed lower δ13C values from −40.0 to −35.5‰, suggesting that the source organisms B. braunii at least partially utilize recycled CO2 (13C depleted) produced from OM respiration rather than atmospheric CO2 (13C enriched) as the major carbon sources

Saccharides in atmospheric particulate and sedimentary organic matter : status overview and future perspectives

Saccharides are omnipresent compounds in terrestrial and marine ecosystems. Since the 2000s, their role in environmental and geochemical studies has significantly increased, but only anhydrosaccharides (mainly levoglucosan) have been reviewed. Here we present the wider knowledge about saccharides in organic matter of aerosols, bottom sediments, soils, dust, and sedimentary rocks. The main purpose here is to characterize the possible sources of saccharides, as well as sacharol formation, seasonal variability, and the possible applications in environmental and paleoenvironmental interpretations. Different saccharide sources were designated, including biomass burning, and particulate matter such as pollen, spores, lichen, and fungi, as well as polysaccharide decomposition as possible inputs of monosaccharides. The main focus was on the most common saccharides encountered in environmental samples and sedimentary rocks. These are the mono- and disaccharides glucose, fructose, sucrose, and trehalose, and sacharols arabitol and mannitol. The anhydrosaccharides levoglucosan, mannosan, and galactosan were evaluated as ancient wildfire indicators and industrialization tracers found in lacustrine sediments starting from Pleistocene to contemporary deposits. However, other anhydrosaccharides like xylosan and arabinosan were also found as products of fossil wood burning. These anhydrosaccharides have the potential to be further tracers of hemicellulose burning. Additional recommendations are proposed for future research, including environmental and paleoenvironmental topics that need to be addressed

Variations in δ13C values of levoglucosan from low-temperature burning of lignite and biomass

Levoglucosan, an anhydrosaccharide, is commonly used as an organic tracer for biomass burning, but has also been identified from coal smoke particulate matter (PM) including lignites. Here we showed that stable carbon isotope analysis specifically of levoglucosan may be one possible way to determine the relative contributions from coal combustion versus biomass burning sources. PM sampleswere collected from low-temperature burning/ smoldering of Miocene lignites from Poland and basket willow (Salix viminalis L.) representative of biomass. The calculated levoglucosan δ13C values of xylites varied from −23.6 to−21.6‰, while for detritic coal samples they ranged from −24.2 to −23.1‰, with means of −22.7 and −23.7‰, respectively. The calculated levoglucosan δ13C value of basketwillow woodwas−27.1‰. Values ofwillowwoodmixtureswith xylite varied from−25.8 to−23.4‰(with an increasing proportion of xylite), while values of mixtures of willow and detritic coal ranged from−26.9 to−24.6‰(with an increasing proportion of detritic coal). The δ13C values for themixtures changed proportionally to the contents of individual components with R2=0.88 and 0.89 for willow with xylite and detritic coal, respectively. The hopanoid distributions characteristic for low-temperature lignite/peat burning, with a predominance of 22R-α,β-homohopane, ββ-hopanes and hopenes, as well as low or very low values of the homohopane index,were observed in smokePMfrommost lignite samples and absent in the basket willow sample. Thus, the relatively high content of hopanes (with the occurrence of 22R-α,β-homohopane, ββ- hopanes and hopenes) in atmospheric PM samples can be treated as additional tracers of lignite combustion

Origin and significance of saccharides during initial pedogenesis in a temperate climate region

Saccharides are common constituents of soils, but their role and origin in the initial phases of pedogenesis remain unclear. Here we show the detailed composition of neutral sugars extracted from arenosols at different development stages, combined with additional lipids of diverse origins using gas chromatography-mass spectrometry (GC–MS). During the first stage (I) of development sucrose is the most abundant saccharide in the soil crust at up to 45,000 μg/g TOC. Sucrose is also the predominant compound in the second and third development stages, but its concentration decreased to the range of 1600 to 16,000 μg/g TOC. Stages II and III of soil development were characterized by a gradual increase in arabitol, mannitol and trehalose, compounds typical for fungi and lichen. Their abundances increased from several percent (compared to the major sucrose) to 10–32% for mannitol and 34–54% for trehalose. Moreover, in stage III there was a considerable increase in the contents of the saccharides: pinitol, myo-inositol, scyllo-inositol, arabinose, together with non-sugar compounds: dehydroabietic acid, p-hydroxybenzoic acid, gallic acid and sitosterol. All these latter compounds are higher plant markers, mainly derived from conifer detritus. The relationships between the ratios of trehalose/sucrose vs. (mannitol + arabitol)/sucrose and TOC vs. (mannitol + arabitol)/sucrose differentiated precisely the top soil layer of arenosols which are covered by different stages of biological soil crust. Our study shows that free sugars, supplemented by lipid biomarkers and total organic carbon contents, are good indicators of soil in the initial phase of pedogenesis

Trehalose, mannitol and arabitol as indicators of fungal metabolism in late Cretaceous and Miocene deposits

Trehalose, mannitol and arabitol are the main saccharides of extant fungal metabolism, but their occurrence and distribution in geological materials have rarely been considered. Here, we identify these sugars in Miocene lignites and for the first time in Late Cretaceous mudstones and coals. The co-occurrence of trehalose, mannitol and arabitol in the sedimentary rocks investigated suggests their fungal origin, because these three saccharides are major compounds present in most modern fungi, including the very common mycorrhizal and wood-rotting groups. Therefore, we conclude that these sugars should be treated as new fungal biomarkers (biomolecules) present in geological rocks. Trehalose and mannitol are major compounds in total extracts of the samples and a sum of their concentration reaches 4.6 μg/g of sample. The arabitol concentrations do not exceed 0.5 μg/g, but in contrast to trehalose, the concentration correlates well with mannitol (R2=0.94), suggesting that they have the same, translocatory role in fungi. Based on the trehalose vs. mannitol and arabitol distributions in Cretaceous samples and their comparison with data for modern fungi, we preliminarily conclude that the coal seams from the Rakowice Małe (SW Poland) section were formed during warmer climatic periods than the overlying sediments. Furthermore, no DNA could be isolated from the samples of lignites and overlying sediments, whereas it was abundant in the control samples of maple, birch and oak wood degraded by fungi. This indicates an absence of recent fungi responsible for decay in lignites and implies that the saccharide origin is connected with ancient fungi. Other sugar alcohols and acids like D-pinitol, quinic acid and shikimic acid, were found for the first time in sedimentary rocks, and their source is inferred to be from higher plants, most likely conifers. The preservation of mono- and disaccharides of fungal origins in pre-Palaeogene strata implies that compounds previously thought as unstable can survive for tens to hundreds of millions of years without structural changes in immature rocks unaffected by secondary processes

Lignite biodegradation under conditions of acidic molasses fermentation

Lignite is difficult to degrade, thus stimulation of the autochthonous lignite microflora and introduction of additional microorganisms are required for lignite decomposition. Here, a packed bed reactor, filled with lignite samples from the Konin region (central Poland) was supplied continuously with M9 medium, supplemented with molasses (a by-product from the sugar industry), for 124 days to stimulate the autochthonous lignite microflora. Acidic fermentation of molasses was observed in the bioreactor. The simultaneous decomposition of lignite occurred under this acidic molasses fermentation condition. Our results show decay of free (non-bound) organic compounds during anaerobic lignite biodegradation. The concentrations of n-alkanes, n-alkanols, n-alkanoic acids, diterpenoids, triterpenoids and steroids present in non-biodegraded samples decreased significantly (some compounds to zero) during biodegradation. Interestingly, other compound classes like phenols, ketones and certain organic compounds increased. We interpret this phenomenon as a gradual decomposition of polymers, lignin and cellulose, present in the lignite. These changes resulted from microbial activity since they were not observed in pure solutions of short-chain fatty acids. The 16SrRNA profiling of the microbial community selected in the bioreactor revealed that the dominant bacteria belonged to the Firmicutes, Actinobacteria, Proteobacteria and Bacteroidetes, furthermore representatives of 16 other phyla were also found. All the known taxa of lignocellulolytic bacteria were represented in the microbial community. Synergistic relations between bacteria fermenting molasses and bacteria degrading lignite are assumed. The results confirm lignin degradation in acidic medium by bacteria under anaerobic conditions

La generación de petróleo hidrotermal en sedimentos del Lago Chapala y su relación con la actividad geotérmica del rift Citala en el estado de Jalisco, México

El Lago de Chapala, ubicado en el occidente de México dentro del Rift Citala, está caracterizado por su actividad geotérmica, la cual incluye manantiales termales terrestres y sublacustres, halos de alteración hidrotermal, depósitos carbonatados tipo sínter y volcanes de lodo. Dentro del Lago de Chapala existen tanto manantiales sublacustres como emanaciones de asfalto que constituyen isletas. Los hidrocarburos que se generan en zonas con actividad geotérmica, continentales y marinas tienen un origen hidrotermal, ya que el agente causante de la alteración de la materia orgánica así como de la transferencia de masa es el agua caliente circulante en el sistema hidrotermal. Por ello, este tipo de hidrocarburo se denomina petróleo hidrotermal (PH). Los análisis del PH del Lago de Chapala, obtenidos por cromatografía de gases acoplada a espectrometría de masas (GC-MS), muestran que está formado por hidrocarburos saturados que incluyen una mezcla compleja amorfa de hidrocarburos cíclicos y ramifi cados (UCM). Los biomarcadores maduros, derivados de la microbiota lacustre (algas), consisten principalmente de hopanos 17"(H),21#(H) desde C27 hasta C34 (sin C28); gammacerano, terpanos tricíclicos (C20-C26, sin C22); carotano y sus productos de cracking primario; esteranos C28 y C29; y drimanos (C14-C16). El PH de Chapala no contiene hidrocarburos policíclicos aromáticos (PAH) ni n-alcanos. La composición de este PH no corresponde a residuos de petróleo convencional biodegradado. Por carecer tanto de n-alcanos como de isoprenoides y por la presencia de UCM, hopanos, esteranos y biomarcadores carotenoides, su composición es similar al PH reportado del Rift del Este de África y consistente con una generación rápida de hidrocarburos. Por lo tanto se infi ere que el PH del Lago de Chapala fue generado rápida- mente a partir de materia orgánica lacustre a una temperatura inferior a la requerida para el cracking primario, por hidrotermalismo, de los alcanos a partir del kerógeno (40 ka (14C). El carbono total del PH del Lago de Chapala tiene una media $13CPDB de -21.4 ¿ que es un valor típico para materia orgánica lacustre. La ocurrencia de PH en sistemas de rifts continentales está plenamente comprendida y, debido a su potencial, debe de ser considerada como blanco a evaluar en la exploración futura de recursos energéticos en estos sistemas tectónicos

Occurrence and distribution of novel botryococcene hydrocarbons in freshwater wetlands of the Florida Everglades

A high abundance of isoprenoid hydrocarbons, the botryococcenes, with carbon numbers from 32 to 34 were detected in the Florida Everglades freshwater wetlands. These compounds were present in varying amounts up to 106 μg/gdw in periphyton, 278 μg/gdw in floc, and 46 μg/gdw in soils. Their structures were determined based on comparison to standards, interpretation of their mass spectra and those of their hydrogenation products, and comparison of Kovats indexes to those reported in the literature. A total of 26 cyclic and acyclic botryococcenes with 8 skeletons were identified, including those with fewer degrees of unsaturation, which are proposed as early diagenetic derivatives from the natural products. This is the first report that botryococcenes occur in the Everglades freshwater wetlands. Their potential biogenetic sources from green algae and cyanobacteria were examined, but neither contained botryococcenes. Thus, the source implication of botryococcenes in this ecosystem needs further study