Production of fuels and chemicals from renewable resources using engineered Escherichia coli

Biotechnological production of fuels and chemicals from renewable resources is an appealing way to move from the current petroleum-based economy to a biomass-based green economy. Recently, the feedstocks that can be used for bioconversion or fermentation have been expanded to plant biomass, microbial biomass, and industrial waste. Several microbes have been engineered to produce chemicals from renewable resources, among which Escherichia coli is one of the best studied. Much effort has been made to engineer E. coli to produce fuels and chemicals from different renewable resources. In this paper, we focused on E. coli and systematically reviewed a range of fuels and chemicals that can be produced from renewable resources by engineered E. coli. Moreover, we proposed how can we further improve the efficiency for utilizing renewable resources by engineered E. coli, and how can we engineer E. coli for utilizing alternative renewable feedstocks. e.g. C1 gases and methanol. This review will help the readers better understand the current progress in this field and provide insights for further metabolic engineering efforts in E. coli.     

Four thousand years of plant exploitation in the Lake Chad Basin (Nigeria), part III: plant impressions in potsherds from the Final Stone Age Gajiganna Culture*

Late Holocene climatic changes caused a large scale regression of the Lake Chad shoreline followed by an expansion of settlements into previously unexplored territories. Numerous Final Stone Age sites of the Gajiganna Culture (1,800 to 800 b.c.) in the Lake Chad Basin (northeast Nigeria) yielded plant impressions in potsherds. The ceramics of Phase I (1,800–1,400 b.c.) were mineral tempered, and plant impressions, mainly of Paniceae, were caused only by incidental inclusion. In contrast, a considerable number of the sherds from Phase II (1,500–800 b.c.) were intentionally tempered with chaff derived from domesticated pearl millet (Pennisetum glaucum), wild Paniceae and wild rice species (Oryza cf. barthii and O. cf. longistaminata). This plant spectrum suggests the exploitation of the wet wild areas, and also the cultivation of pearl millet on sandy soils. The evidence suggests that agricultural practices were established late and were introduced from elsewhere. During the time of seasonally occupied sites in Phase I, the subsistence strategy was based on herding, fishing, and gathering, while in Phase II there are signs of permanent settlements and agriculture. The evidence from the plant impressions indicates that in the Final Stone Age Gajiganna Culture around 1,000–800 b.c., pearl millet became well established while the gathering of wild millets and rice was still practised.*Klee et al. (2000), Zach and Klee (2003)     

Impact of West Nile Virus on American Crows in the Northeastern United States,and Its Relevance to Existing Monitoring Programs

We assessed the changes in abundance of American crows in the northeastern U.S. following the arrival of West Nile virus (WNV), with two aims. First, we determined the impact and spatial extent of the initial epizootic that began in New York City. Second, we examined whether two existing surveillance programs monitoring for WNV (data from 2000 New York State dead bird testing, and 2000 mosquito testing) accurately predicted the observed impact of the disease on crow populations as measured using data from the North American Christmas Bird Count. The rationale for this second aim was that the two WNV surveys were new and with unknown biases and sensitivity, while the Christmas Bird Count has existed for decades, providing monitoring before the arrival of WNV in North America and a long time series of data useful in gauging sensitivity. As a result, the Christmas Bird Count represents a good benchmark against which to compare the two new surveillance programs. Consistency among these three sources of information was low, suggesting that while dead bird and mosquito surveys can currently indicate the later stages of severe outbreaks, the ability to consistently detect early stages of outbreaks is questionable.     

Revision of the genus Clibadium (Asteraceae, Heliantheae)

Clibadium L. (Asteraceae, Heliantheae) is a genus of 29 species distributed throughout latin America, from Mexico to Peru, and in the West Indies, with high numbers of species in Costa Rica, Colombia, and Ecuador.Clibadium includes shrubs and small trees; usually with loosely aggregated capitula; herbaceous phyllaries arranged in 1–5 series; receptacles usually paleaceous throughout; corollas of pistillate florets 2–4-lobed; corollas of the staminate florets 4–5-lobed; purple to black anthers; and chromosome numbers alln=16. Two sections of species previously recognized are here considered as subgenera (subg.Paleata and subg.Clibadium) containing two and four sections, respectively.Clibadium subg.Paleata contains five species distributed in sects.Eggersia (3 spp.) andTrixidium (2 spp.), and subg.Clibadium has 24 species distributed among sects.Clibadium (6 spp.),Glomerata (9 spp.),Grandifolia (5 spp.), andOswalda (4 spp.).     

Morphological variation in populations of Bletia purpurea (Orchidaceae) and description of the new species B. riparia

Bletia purpurea is the most widespread species in its genus. Morphological variation has been recognized throughout the range of its distribution. In this paper, the morphological variation from 63 populations (583 individuals) ofBletia purpurea is assessed to determine whether more than one species were present. Forty-four quantitative and qualitative characters were examined by univariate analyses and exploratory multivariate analyses. Univariate analyses indicate that quantitative characters such as lateral sepal width, petal. width, lip length, and lip width are significantly different for populations from Acazónica, Mexico. Floral parts in the populations from Acazónica are the smallest among all populations. Qualitative characters such as petals covering the lip midlobe and horizontal lip position are found exclusively in the same populations. We concluded that these populations should be described as a new species,B. riparia. Multivariate analyses indicated that morphological variation among the other populations cannot be ascribed to geographic distribution or ecological factors.     

A review of the chronostratigraphical ages of Middle Triassic to Late Jurassic dinoflagellate cyst biozones of the North West Shelf of Australia

The chronostratigraphical ages of the 20 dinoflagellate cyst zones and one dinoflagellate cyst assemblage for the Middle Triassic (Ladinian) to the Jurassic-Cretaceous transition of the North West Shelf of Australia are comprehensively reviewed. Evidence from macro- and micropalaeontology, palynology and strontium isotopes made available after the establishment of these biozones in the 1980s has been used to reassess the ages of this important zonal scheme and to calibrate it to the international stratigraphical stages. The Shublikodinium Superzone is renamed herein as the Rhaetogonyaulax Superzone, and based on conodont evidence is determined to span the Ladinian to Early Sinemurian. This is significantly shorter in duration than was originally envisaged (Late Anisian to Late Pliensbachian). The Luehndea Assemblage is a low diversity dinoflagellate cyst association which marks a eustatic rise; it is subdivided into two subzones. It is of latest Pliensbachian to Early Toarcian age, based largely on palynological evidence. The Bajocian to earliest Oxfordian Pareodinia ceratophora Superzone represents the inception of a continuous Mesozoic-Cenozoic dinoflagellate cyst record in Australia. It comprises seven zones, which are considered to be slightly older than originally interpreted. The overlying Pyxidiella Superzone is characterised by diverse dinoflagellate cyst associations. It is Early Oxfordian to Kimmeridgian in age, and comprises three zones. The bases of the Wanaea spectabilis and Wanaea clathrata zones are reinterpreted as being slightly older than originally proposed. The superjacent Fromea cylindrica Superzone is Tithonian to earliest Valanginian and modified ages are indicated for four of the nine zones. This unit is dominated by endemic dinoflagellate cysts, reflecting a global trend towards provincialism at this time due to a regressive eustatic regime.     

West Nile Virus Exposure in Black Bears of Northeastern Wisconsin

ABSTRACT Knowledge of the distribution and pathology of West Nile virus (WNV) in black bears is a necessary tool that allows wildlife managers to implement a management plan, set harvest quotas, and relocate nuisance bears. We studied the presence and significance of WNV titers in free-roaming black bears (Ursus americanus) in northeastern Wisconsin between February 2003 and March 2005. Serum neutralizing antibodies to WNV, with confirmation by plaque-reduction neutralization test to both WNV and Saint Louis encephalitis, identified exposure in 13 of 74 (17.6%) bears. This compares with a 6% infection rate in black bears in Virginia and 22% in European brown bears (Ursus arctos). Pathologic effects from exposure to WNV were not seen in any of the black bears studied.     

Morphometric divergence in populations of Anastrepha obliqua (Diptera,Tephritidae) from Colombia and some Neotropical locations

The West Indian fruit fly, Anastrepha obliqua, is one of seven species of quarantine importance of its genus and is one of the most economically important fruit fly pests in Colombia. The taxonomic status of this species is a key issue for further implementation of any pest management program. Several molecular studies have shown enough variability within Anastrepha obliqua to suggest its taxonomic status could be revised; however, there are no morphological studies supporting this hypothesis. The aim of this work was to describe the morphological variability of Colombian populations of Anastrepha obliqua, comparing this variability with that of other samples from the Neotropics. Measurements were performed on individuals from 11 populations collected from different geographic Colombian localities and were compared with populations from Mexico (2), Dominica Island (1), Peru (1) and Brazil (2). Linear morphometric analyses were performed using 23 female morphological traits, including seven variables of the aculeus, three of the thorax, and six of the wing; seven ratios among them were also considered. Discriminant function analyses showed significant morphological differentiation among the Colombian populations, separating them into two groups. Furthermore, in the comparisons between Colombian samples with those from other countries, three clusters were observed. The possibility of finding more than one species within the nominal Anastrepha obliqua population is discussed.