Enumeration and isolation of cellulolytic and hemicellulolytic bacteria from human feces

The fibrolytic microbiota of the human large intestine was examined to determine the numbers and types of cellulolytic and hemicellulolytic bacteria present. Fecal samples from each of five individuals contained bacteria capable of degrading the hydrated cellulose in spinach and in wheat straw pretreated with alkaline hydrogen peroxide (AHP-WS), whereas degradation of the relatively crystalline cellulose in Whatman no. 1 filter paper (PMC) was detected for only one of the five samples. The mean concentration of cellulolytic bacteria, estimated with AHP-WS as a substrate, was 1.2 X 10(8)/ml of feces. Pure cultures of bacteria isolated on AHP-WS were able to degrade PMC, indicating that interactions with other microbes were primarily responsible for previous low success rates in detecting fecal cellulolytic bacteria with PMC as a substrate. The cellulolytic bacteria included Ruminococcus spp., Clostridium sp., and two unidentified strains. The mean concentration of hemicellulolytic bacteria, estimated with larchwood xylan as a substrate, was 1.8 X 10(10)/ml of feces. The hemicellulose-degrading bacteria included Butyrivibrio sp., Clostridium sp., Bacteroides sp., and two unidentified strains, as well as four of the five cellulolytic strains. This work demonstrates that many humans harbor intestinal cellulolytic bacteria and that a hydrated cellulose source such as AHP-WS is necessary for their consistent detection and isolation.     

Enumeration and isolation of cellulolytic and hemicellulolytic bacteria from human feces.

The fibrolytic microbiota of the human large intestine was examined to determine the numbers and types of cellulolytic and hemicellulolytic bacteria present. Fecal samples from each of five individuals contained bacteria capable of degrading the hydrated cellulose in spinach and in wheat straw pretreated with alkaline hydrogen peroxide (AHP-WS), whereas degradation of the relatively crystalline cellulose in Whatman no. 1 filter paper (PMC) was detected for only one of the five samples. The mean concentration of cellulolytic bacteria, estimated with AHP-WS as a substrate, was 1.2 X 10(8)/ml of feces. Pure cultures of bacteria isolated on AHP-WS were able to degrade PMC, indicating that interactions with other microbes were primarily responsible for previous low success rates in detecting fecal cellulolytic bacteria with PMC as a substrate. The cellulolytic bacteria included Ruminococcus spp., Clostridium sp., and two unidentified strains. The mean concentration of hemicellulolytic bacteria, estimated with larchwood xylan as a substrate, was 1.8 X 10(10)/ml of feces. The hemicellulose-degrading bacteria included Butyrivibrio sp., Clostridium sp., Bacteroides sp., and two unidentified strains, as well as four of the five cellulolytic strains. This work demonstrates that many humans harbor intestinal cellulolytic bacteria and that a hydrated cellulose source such as AHP-WS is necessary for their consistent detection and isolation.     

Bioprocess design and economic analysis for the commercial production of environmentally friendly bioinsecticides from Bacillus thuringiensis HD-1 kurstaki

A production process for B. thuringiensis (Bt) bioinsecticides was designed in detail, including alternative batch, low-density fed-batch (LDFB), and high-density fed-batch (HDFB) fermentation configurations. Capital and operating costs, as well as profitability based on simple rate of return, were performed using a purpose-written FORTRAN program, explicitly analyzing production of a water-based flowable product used in forestry applications.The total capital cost was 18 million dollars (Canadian dollars) for a stand-alone plant with base-scale capacity of 3 x 10(7) billion international units (BIU)/year. Raw material costs amounted to 1.5 million dollars yearly, of which approximately half was for formulation ingredients. Per-unit production cost rose sharply for scales of less than 1 x 10(7) BIU/year, but was little affected by scale above 3 x 10(7) BIU/year. Product cost was much lower at all scales for a LDFB as opposed to batch fermentation process, but HDFB gave relatively little additional cost benefit. Profitability analysis performed by co-varying scale and selling price showed that break-even occurred at a price of 0.45 dollars/BIU for a batch process at base scale, while with LDFB fermentation the same production volume sold at 0.35 dollars/BIU gave a 12% rate of return. Since the assumed base scale would represent 8-15% of current world Bt bioinsecticide production, based on value or volume, it was concluded that profitability would require some or all of the following elements: targeting higher-value markets such as disease vector control, in addition to forestry; a potentially lower plant capacity (although at least 1 x 10(7) BIU/year;) and coproduction of other large-volume microbial products to absorb capacity and match bioinsecticide output to market demand.     

Interactions between Treponema bryantii and cellulolytic bacteria in the in vitro degradation of straw cellulose

To assess the contribution of individual bacterial species to the overall process of cellulose digestion in the rumen, cellulolytic bacteria (Bacteroides succinogenes and Ruminococcus albus) were tested as pure cultures and as cocultures with noncellulolytic Treponema bryantii. In studies of in vitro barley straw digestion, Treponema cocultures surpassed pure cultures of the cellulolytic organisms in dry matter disappearance, volatile fatty acid generation, and in the production of succinic acid, lactic acid, and ethanol. Morphological examination, by electron microscopy, showed that cells of T. bryantii associate with the plant cell wall materials in straw, but that cellulose digestion occurs only when these organisms are present with cellulolytic species such as B. succinogenes. These results show that cellulolytic bacteria interact with noncellulolytic Treponema to promote the digestion of cellulosic materials.     

Current Estimates of the Economic Cost of Obesity in the United States

This study was undertaken to update and revise the estimate of the economic impact of obesity in the United States. A prevalence-based approach to the cost of illness was used to estimate the economic costs in 1995 dollars attributable toobesity for type 2 diabetes mellitus, coronary heart disease (CHD), hypertension, gallbladder disease, breast, endometrial and colon cancer, and osteoarthritis. Additionally and independently, excess physician visits, work-lost days, restricted activity, and bed-days attributable to obesity were analyzed cross-sectionally using the 1988 and 1994 National Health Interview Survey (NHIS). Direct (personal health care, hospital care, physician services, allied health services, and medications) and indirect costs (lost output as a result of a reduction or cessation of productivity due to morbidity or mortality) are from published reports and inflated to 1995 dollars using the medical component of the consumer price index (CPI) for direct cost and the all-items CPI for indirect cost. Population-attributable risk percents (PAR%) are estimated from large prospective studies. Excess work-lost days, restricted activity, bed-days, and physician visits are estimated from 88,262 U. S. citizens who participated in the 1988 NHIS and 80,261 who participated in the 1994 NHIS. Sample weights have been incorporated into the NHIS analyses, making these data generalizable to the U. S. population. The total cost attributable to obesity amounted to $99. 2 billion dollars in 1995. Approximately $51. 64 billion of those dollars were direct medical costs. Using the 1994 NHIS data, cost of lost productivity attributed to obesity (BMI≥30) was $3. 9 billion and reflected 39. 2 million days of lost work. In addition, 239 million restricted-activity days, 89. 5 million bed-days, and 62. 6 million physician visits were attributable to obesity in 1994. Compared with 1988 NHIS data, in 1994 the number of restricted-activity days (36%), bed-days (28%), and work-lost days (50%) increased substantially. The number of physician visits attributed to obesity increased 88% from 1988 to 1994. The economic and personal health costs of overweight and obesity are enormous and compromise the health of the United States. The direct costs associated with obesity represent 5. 7% of our National Health Expenditure in the United States .     

Switchgrass (Panicum vigratum, L.) delivery to a biorefinery using integrated biomass supply analysis and logistics (IBSAL) model

This study develops cost, energy input and carbon emissions for a number of switchgrass supply options. The Integrated Biomass Supply Analysis and Logistics (IBSAL) model developed at Oak Ridge National Laboratory is used to evaluate the delivery systems. Three biomass collection systems: baling, loafing and ensiling are evaluated. The number and operational performance of equipment are specified to complete collection operations within 120 days of harvest after August 1. Bales are stacked and tarped on the farm side. The transport of biomass from the farm side to a biorefinery takes place over a full year cycle, i.e. 365 days. Supply quantities range from 454 to 4540 dry tonnes/day (500-5000 dry tons/day). Delivered costs to a biorefinery with capacity of 1814 dry tonnes/day (2000 dry tons/day) are: 44-47 dollars/dry tonne for delivered bales (round and square); 37 dollars/dry tonne for delivered loafs (size 2.4 m x 3.6 m x 6 m); 40 dollars/dry tonne for chopped biomass; and 48 dollars/dry tonne for ensiled chops. These costs do not include any payment to the farmers or switchgrass farming cost. Based on the data from literature, the switchgrass farming cost can range from 30 to 36 dollars/dry tonne. These costs would be additional to the switchgrass collection and transportation cost. Switchgrass collection is generally less expensive than collection of straw or corn stover because of the assumed high yield of 11 dry tonnes/ha and a denser biomass. Energy consumption for delivery systems at this capacity ranges from 4.8% to 6.3% of the energy content of switchgrass. Additional 1% of the energy content of switchgrass is consumed in its farming. At 1814 dry tonnes/day (2000 dry tons/day) capacity, greenhouse gas emissions ranges from 75 to 100 kg of CO2/dry tonne of switchgrass delivered.     

The Chikungunya epidemic on La Réunion Island in 2005-2006: a cost-of-illness study

Background

This study was conducted to assess the impact of chikungunya on health costs during the epidemic that occurred on La Réunion in 2005–2006.

Methodology/Principal Findings

From data collected from health agencies, the additional costs incurred by chikungunya in terms of consultations, drug consumption and absence from work were determined by a comparison with the expected costs outside the epidemic period. The cost of hospitalization was estimated from data provided by the national hospitalization database for short-term care by considering all hospital stays in which the ICD-10 code A92.0 appeared. A cost-of-illness study was conducted from the perspective of the third-party payer. Direct medical costs per outpatient and inpatient case were evaluated. The costs were estimated in Euros at 2006 values. Additional reimbursements for consultations with general practitioners and drugs were estimated as €12.4 million (range: €7.7 million–€17.1 million) and €5 million (€1.9 million–€8.1 million), respectively, while the cost of hospitalization for chikungunya was estimated to be €8.5 million (€5.8 million–€8.7 million). Productivity costs were estimated as €17.4 million (€6 million–€28.9 million). The medical cost of the chikungunya epidemic was estimated as €43.9 million, 60% due to direct medical costs and 40% to indirect costs (€26.5 million and €17.4 million, respectively). The direct medical cost was assessed as €90 for each outpatient and €2,000 for each inpatient.

Conclusions/Significance

The medical management of chikungunya during the epidemic on La Réunion Island was associated with an important economic burden. The estimated cost of the reported disease can be used to evaluate the cost/efficacy and cost/benefit ratios for prevention and control programmes of emerging arboviruses.     

The Maceration of Linen Flax under Anaerobic Conditions

Ret tanks of 350 1 capacity, loaded with 14 kg of flax straw and maintained at 32°C. were sampled at regular intervals for 90 h. Total numbers of bacteria and viable anaerobes increased rapidly during the initial 16 h, reached a maximum at 22 h and then remained constant in the ret liquor. They continued to increase at a reduced rate within the flax straw. Dissolved oxygen content and pH of the ret liquor fell rapidly over the initial period while volatile fatty acids, ammonia and methanol accumulated. Xylanolytic and cellulolytic bacteria were detected in increasing numbers after 40 h. Pectinesterase (PE.EC. 3.1.1.11) was restricted largely to the flax straw where activity developed in parallel with microbial growth, reached a maximum at 22 h and rapidly declined thereafter. Polygalacturonase (PG.EC. 3.2.1.15/40) and pectate lyase (PAL.EC.4.2.2.1/2) activities developed after 16 h when soluble carbohydrates had been depleted. Higher levels of both activities were associated with the flax straw than with the ret liquor. PG predominated over PAL activity throughout. Other glycan hydrolyase activities were not detected. Fractionation and analysis of straw samples showed that 83% of pectic polyuronide present at the start of the ret was degraded by 70 h, whereas 16% of the hemicellulose and none of the cellulose was lost over the same period.     

Cellulolytic bacteria in buffalo rumen

The influence of three different feeds, wheat straw, sorghum and berseem, on total and cellulolytic bacterial counts in the buffalo rumen at different time intervals from 0 to 8 h after feeding was studied. Berseem feeding supported maximum growth of rumen bacteria in general and cellulolytic bacteria in particular. Wheat straw supported the poorest growth.
The types of cellulolytic bacteria recovered from the rumen of adult buffaloes were Ruminococcus albus, R. flavefaciens, Bacteroides succinogenes, Butyrivibrio fibrisolvens, Clostridium lochheadii, Cl. longisporum and other Clostridium spp. Cellulolytic cocci were present in smaller numbers than rod forms in the rumen of wheat-straw-fed buffaloes, whereas the cocci outnumbered rod forms in sorghum-and berseem-fed buffaloes.     

Current and projected annual direct costs of screening asymptomatic men for prostate cancer using prostate-specific antigen

BACKGROUND: Concern over the cost of screening for asymptomatic prostate cancer by means of prostate-specific antigen (PSA) testing has played an important role in PSA screening policy. However, little is known about the true costs of current PSA screening in Canada and how costs may change in the future. METHODS: The authors performed a cost identification study from the perspective of provincial ministries of health. They used data from published reports, hospital discharge data, claims data from several provinces, a laboratory survey, a national survey of knowledge, attitudes and beliefs about screening, a provincial cancer registry and expert opinion to estimate current first-year screening costs. Using demographic data from Statistics Canada and various scenarios regarding changes in screening patterns, the authors derived estimates of the future costs of PSA screening. RESULTS: In 1995 PSA screening cost an estimated $45 million (range $40 million to $84 million). Treatment accounted for over 61% of total costs, whereas screening, diagnosis and staging accounted for 35%. Screening all eligible men in Canada in 1995 would have cost $317 million (range $356 million to $691 million), more than the costs of all prostate cancer care in that year. Annual recurrent screening for all eligible men in 2005 would cost $219 million (range $208 million to $412 million). Projections from existing trends suggest that annual costs of PSA screening in 2000 are likely to increase from the estimated $45 million to approximately $66 million (range $59 million to $126 million). INTERPRETATION: PSA screening is costly, but even universal screening would consume a smaller share of national health expenditures than previous studies have suggested. Costs attributable to PSA screening may increase in the future owing to changes in utilization patterns and demographic shifts.     

Reutilization of enzymes for saccharification of lignocellulosic materials

Enzymic hydrolysis of steam-exploded wheat straw is initially a fast process which gradually slows down. Since the cellulolytic enzymes account for 60% of the processing costs incurred during saccharification of lignocellulosics, recirculation of these enzymes is clearly necessary. It is demonstrated that the cellulolytic enzymes have a high affinity for the remaining lignin. Only 50% of the added enzymes are free in solution after almost complete hydrolysis of the straw polysaccharides. Elution of the enzymes from the lignin can result in a total enzyme recovery of up to 90%. However, it is questionable whether elution of enzymes from the lignin is economically feasible as a technical process.     

Costs associated with gunshot wounds in Canada in 1991.

OBJECTIVE: To estimate the costs (in 1993 dollars) associated with gunshot wounds in Canada in 1991. DESIGN: Cost analysis using separate estimates of gunshot incidence rates and costs per incident for victims who died, those who survived and were admitted to hospital and those who survived and were treated and released from emergency departments. Estimates were based on costs for medical care, mental health care, public services (i.e., police investigation), productivity losses, funeral expenses, and individual and family pain, suffering and lost quality of life. SETTING: Canada. OUTCOME MEASURES: Costs per case, costs by type of incident (e.g., assault, suicide or unintentional shooting) and costs per capita. RESULTS: The total estimated cost associated with gunshot wounds was $6.6 billion. Of this, approximately $63 million was spent on medical and mental health care and $10 million on public services. Productivity losses exceeded $1.5 billion. The remaining cost represented the value attributed to pain, suffering and lost quality of life. Suicides and attempted suicides accounted for the bulk of the costs ($4.7 billion); homicides and assaults were the next most costly ($1.1 billion). The cost per survivor admitted to hospital was approximately $300,000; this amount included just over $29,000 for medical and mental health care. CONCLUSION: Costs associated with gunshot wounds were $235 per capita in Canada in 1991, as compared with $595 in the United States in 1992. The differences in these costs may be due to differences in gun availability in the two countries. This suggests that increased gun control may reduce Canada''s costs, especially those related to suicide.     

Accelerated evolution in bacterial endosymbionts of aphids.

When compared with free living bacteria, it is proposed that there are at least two endosymbiotic processes in aphids based on the A + T content as well as the increased evolutionary rate of the beta-subunit of the F-ATPase complex in different endosymbiotic bacteria. The first well established process corresponds to the integration of Buchnera aphidicola more than 150 million years ago. The other is postulated to correspond to new endosymbiotic processes in which the bacteria involved contain less A + T and show a lower increase of evolutionary rates when compared with B. aphidicola. It is proposed, therefore, that endosymbioses are active processes in aphid evolution.     

Cost-of-illness analysis of type 2 diabetes mellitus in Iran

Introduction

Diabetes is a worldwide high prevalence chronic progressive disease that poses a significant challenge to healthcare systems. The aim of this study is to provide a detailed economic burden of diagnosed type 2 diabetes mellitus (T2DM) and its complications in Iran in 2009 year.

Methods

This is a prevalence-based cost-of-illness study focusing on quantifying direct health care costs by bottom-up approach. Data on inpatient hospital services, outpatient clinic visits, physician services, drugs, laboratory test, education and non-medical cost were collected from two national registries. The human capital approach was used to calculate indirect costs separately in male and female and also among different age groups.

Results

The total national cost of diagnosed T2DM in 2009 is estimated at 3.78 billion USA dollars (USD) including 2.04±0.28 billion direct (medical and non-medical) costs and indirect costs of 1.73 million. Average direct and indirect cost per capita was 842.6±102 and 864.8 USD respectively. Complications (48.9%) and drugs (23.8%) were main components of direct cost. The largest components of medical expenditures attributed to diabetes''s complications are cardiovascular disease (42.3% of total Complications cost), nephropathy (23%) and ophthalmic complications (14%). Indirect costs include temporarily disability (335.7 million), permanent disability (452.4 million) and reduced productivity due to premature mortality (950.3 million).

Conclusions

T2DM is a costly disease in the Iran healthcare system and consume more than 8.69% of total health expenditure. In addition to these quantified costs, T2DM imposes high intangible costs on society in terms of reduced quality of life. Identification of effective new strategies for the control of diabetes and its complications is a public health priority.     

Screening microbial strain for improving the nutritional value of wheat and corn straws as animal feed

From 18 strains of cellulolytic microorganisms including bacteria and filamentous fungi, one strain of soft rot fungus identified as Chaetomium cellulolyticum was screened with respect to stronger decomposition ability of cellulose and hemicellulose and its ability for protein synthesis. As it grew on raw corn straw in solid layer fermentation (SLF) for 5 days, the amino acid content in the fermentation product attained 19.29% (w/w) from 6.43% while the total cell wall was reduced by 54%. A toxicity test with mice showed that the fermentation product is not poisonous. The two filamentous fungi, Trichoderma pseudokoningii S-38 and Penicillium decumbens JU-A10 produced large amounts of extracellular cellulase and hemicellulase in the SLF process, but their growth was limited and they sporulated profusely with regard to their value as animal feed products.     

Incorporating costs in LCA

The goal of LCA is to identify the environmental impacts resulting from a product, process, or activity. While LCA is useful for evaluating environmental attributes, it stops short of providing information that business managers routinely utilize for decision-making — i.e., dollars. Thus, decisions regarding the processes used for manufacturing products and the materials comprising those products can be enhanced by weaving cost and environmental information into the decision-making process. Various approaches have been used during the past decade to supplement environmental information with cost information. One of these tools is environmental accounting, the identification, analysis, reporting, and use of environmental information, including environmental cost data. Environmental cost accounting provides information necessary for identifying the true costs of products and processes and for evaluating opportunities to minimize those costs. As demonstrated through two case studies, many companies are incorporating environmental cost information into their accounting systems to prioritize investments in new technologies and products.     

Cereal supplementation modified the fibrolytic activity but not the structure of the cellulolytic bacterial community associated with rumen solid digesta

4 ruminally cannulated cows were fed a forage diet (93% hay + 7% straw) and a mixed diet (33 % hay + 7% straw + 40% barley) in a 2 x 2 crossover experimental design. In sacco degradation of forage, fibrolytic activities (polysaccharidases and glycosidases) of the solid-associated bacteria (SAB), and distribution of the 3 main cellulolytic bacterial species (Fibrobacter succinogenes, Ruminococcus albus, Ruminococcus flavefaciens) were determined for both diets. Barley supplementation decreased the hay degradation rate and mainly the polysaccharidase activities of the SAB (30% on average). The sum of rRNA of the 3 cellulolytic bacterial species represented on average 17% of the total bacterial signal and R. albus was the dominant cellulolytic bacterial species of the 3 studied. Barley supplementation did not modify the proportion of the 3 cellulolytic bacteria attached to plant particles. The negative effect of barley on the ruminal hay degradation rate is due to a decrease in fibrolytic activity of the SAB, and not to a modification of the balance of the three cellulolytic bacterial species examined.     

An economic analysis of leachate purification through willow-coppice vegetation filters

In this study an economic analysis of the purification of integrated solid waste treatment facility leachates through a willow-coppice (Salix) vegetation filter in southern Sweden was carried out. Calculations were based on the use of two computer models that were initially used in estimating a pump-and-pipe irrigation system for a 36-ha willow-coppice plantation to purify an average annual quantity of 195,000 m(3) of leachate with an average nitrogen content of 24 g/m(3). Results showed that facility leachates could be purified at US dollars 0.34/m(3) compared with US dollars 0.62/m(3) for that of conventional leachate treatment at a wastewater treatment plant. Furthermore, results revealed that the increased income from willow growing and sale of the biomass chips represented only a small factor in the overall cost of the purification technique--decreasing purification costs to US dollars 0.326/m(3). Sensitivity analyses also demonstrated that, because of the large leachate holding pond expense, only a fraction of facility leachate should be treated through a vegetation filter.     

Effect of oxygen concentration on dinitrogen fixation and volatile fatty acid production by Clostridium butyricum growing in association with fungi on cellulose and on wheat straw

Clostridium butyricum was grown with cellulolytic fungi on the substrates wheat straw and cellulose at a range of oxygen concentrations. The straw was not sterile and was inoculated with Sodaria alcina while the cellulose was sterile and was inoculated with Trichoderma harzianum as examples of cellulolytic organisms. The straw subsequently developed a mixed fungal population. Dinitrogen fixation was only significant at a reduced oxygen concentration: optima being 9.3 and 2.3% O₂ for the straw and cellulose experiments, respectively. The efficiencies of N, fixation were 6 mg N per g straw decomposed and 2.3 mg N per g cellulose decomposed and N, fixation occurred only in the presence of significant cellulolysis. Both acetate and butyrate formation increased as the oxygen concentration decreased. With cellulose as a substrate, their formation correlated with a decrease in pH and an increase in final numbers of Cl. butyricum . The thickness of the anaerobic zone at the aerobic/anaerobic interface was linearly related to the square root of the oxygen concentration at the surface of the interface.     

嗜热厌氧纤维素降解细菌的分离、鉴定及其系统发育分析

利用纤维素降解细菌和纤维素粘附的方法分别从新鲜牛粪、高温堆肥和本实验室保存的纤维素降解富集物中分离得到4株嗜热厌氧纤维素降解细菌。分离菌株为革兰氏染色阴性,直的或稍弯曲杆菌,菌体大小为0.4μm～0.6μm×3μm～15μm,严格厌氧,不还原硫酸盐,形成芽孢。多数芽孢着生于菌体顶端。分离菌株能利用纤维素滤纸、纤维素粉Whatman CFII、微晶纤维素、纤维素粉MN300和未经处理的玉米秆芯、甘蔗渣、水稻秸杆。分离菌株在pH6.2～8.9、温度45℃～65℃范围内利用纤维素,最适pH为7.0～7.5,最适温度为55℃～60℃,发酵纤维素产生乙醇、乙酸、H2和CO2。分离菌株还可利用纤维二糖、葡萄糖、果糖、麦芽糖、山梨醇作为碳源。部分长度的16S rDNA序列分析表明,分离菌株EVAI与Clostridium thermocellum具有99.8%相似性。