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The article discusses the evolution in the implementation of stop and frisk policies in cities like New York, New York, Philadelphia, Pennsylvania, and Chicago, Illinois. Also cited are the case Terry v. Ohio in which the U.S. Supreme Court ruled that the action of the police in stopping and frisking two men due to suspicious behavior were warranted and affirmed a lower court's denial of suppression ruling.

The article looks at the prevalence and risk factors of burnout among urologists and proposes several preventative measures and solutions. Literature on this topic in the PubMed database was analyzed. According to the article, high burnout and low work-life satisfaction ranked the highest among urologists. Residency training burnout and suggestions on what the Canadian Urological Association (CUA) can do to help are mentioned.

Microalgae represents a promising biofuel feedstock as it can be cultivated on low-quality land and integrated with a variety of waste streams. Produced water is the largest waste stream generated in the oil and gas industry. The integration of the two systems is synergistic as algal cultivation requires large volumes of water and there is a need for remediation of produced water. Produced water contains inorganic and organic contaminants that could inhibit growth and lipid production of microalgae directly impacting the yield of the system. In this study, produced water from the Uintah Basin, Utah, oil and gas industry was substituted for water in the growth media for microalgae, Nannochloropsis salina. Experiments utilized produced water as the base for media preparation and evaluated microalgae productivity at different dilutions with deionized water, i.e., 0% (control), 25%, 50%, 75%, and 100% produced water, as well as the recycling of produced waterbased growth media. Results show that produced water severely inhib its the growth of microalgae, with a 102% decrease in the 100% produced water media. Recycling of growth media has the potential to positively impact productivity results at concentrations of produced water less than 25%. Discussion focuses on the importance of integration studies, the impact of reduced productivity with higher concentration of produced water, and the need for further experimental growth studies. [ABSTRACT FROM AUTHOR]

The American Committee to Keep Biafra Alive (ACKBA) was the largest and most influential organization in the United States that formed in response to the Nigerian civil war. While historians have pointed to the committee as an important source of activism that pushed the American government towards supporting more vigorous humanitarian relief, this is the first article to explore the development of the group from its inception and to look specifically at its claims of genocide. Not everyone at the time agreed that the Nigerian government was committing genocide against the people living in the secessionist state of Biafra, and that debate continues today. The ACKBA, appealing to genocide prevention and human rights, argued that the debate about the semantics of genocide got in the way of actually helping those that were suffering from famine as a result of the war. In the process, the committee offered a redefinition of genocide that wedded conceptions of Biafran identity to the Biafran state, which made the maintenance of ‘one Nigeria’, in the eyes of committee members, an act of genocide. In the end, this redefinition of genocide failed to bring more people in the United States towards supporting Biafran secession and might have, in the end, led to more confusion about genocide during the conflict. An analysis of the committee's activism highlights the often tenuous relationship between self-determination and genocide in the developing world and illustrates the growing limits of American political intervention in the global south. [ABSTRACT FROM PUBLISHER]

Abstract: The effects of mild conventional food-processing conditions on Listeria monocytogenes survival to pulsed UV (PUV) irradiation and virulence-associated characteristics were investigated. Specifically, this study describes the inability of 10 strains representative of 3 different culture forms or morphotypes of L. monocytogenes to adapt to normally lethal levels of PUV-irradiation after exposure to sub-lethal concentrations of salt (7.5% (w/v) NaCl for 1 h), acid (pH 5.5 for 1 h), heating (48 °C for 1 h) or PUV (UV dose 0.08 μJ/cm2). Findings showed that the order of increasing sensitivity of L. monocytogenes of non-adapted and stressed morphotypes to low pH (pH 3.5 for 5 h, adjusted with lactic), high salt (17.5% w/v NaCl for 5 h), heating (60 °C for 1 h) and PUV-irradiation (100 pulses at 7.2 J and 12.8 J, equivalent to UV doses of 2.7 and 8.4 μJ/cm2 respectively) was typical wild-type smooth (S/WT), atypical filamentous rough (FR) and atypical multiple-cell-chain (MCR) variants. Exposure of L. monocytogenes cells to sub-lethal acid, salt or heating conditions resulted in similar or increased susceptibility to PUV treatments. Only prior exposure to mild heat stressing significantly enhanced invasion of Caco-2 cells, whereas subjection of L. monocytogenes cells to combined sub-lethal salt, acid and heating conditions produced the greatest reduction in invasiveness. Implications of these findings are discussed. This constitutes the first study to show that pre-exposure to mild conventional food-processing stresses enhances sensitivity of different culture morphotypes of L. monocytogenes to PUV, which is growing in popularity as an alternative or complementary approach for decontamination in the food environment. [Copyright &y& Elsevier]

Abstract: Objective: Due to imprecise clinical staging, the finding of extravesical and node-positive disease at the time of radical cystectomy (RC) for patients with clinically localized bladder cancer is not uncommon. Circulating tumor cells (CTCs) have been shown to be present in the peripheral blood of patients with metastatic urothelial carcinoma. The object of this study was to evaluate the ability of CTCs to predict extravesical disease in bladder cancer patients prior to RC. Materials and methods: Peripheral blood samples from 43 patients with bladder cancer were evaluated using the CellSearch (Veridex, LLC, Raritan, NJ) CTC assay prior to RC. The sensitivity, specificity, and positive predictive value (PPV) of CTC status in predicting extravesical disease was calculated. Receiver operating characteristic (ROC) curves were generated to quantify the ability of CTCs to predict extravesical and node-positive disease. Results: CTCs were detected in 9 (21%) patients prior to RC. The sensitivity, specificity, and PPV of CTC status in predicting extravesical disease were 27%, 88% and 78%, respectively. The accuracy of CTC status in predicting extravesical (≥pT3 or node-positive) disease for the entire cohort was 0.576. In a model incorporating preoperative hydronephrosis, CTC status did not improve the predictive accuracy for extravesical disease (0.576 vs. 0.585, P = 0.915). Conclusion: CTCs were detected in low numbers in a small percentage (21%) of patients prior to undergoing RC at our institution. CTC status was not a robust predictor of extravesical or node-positive disease in this cohort. CTC status is not likely to be a clinically useful parameter for directing therapeutic decisions in patients with ≤cT2 bladder cancer. [Copyright &y& Elsevier]

There is considerable interest in exploiting the novel physical and biological properties of microbial exopolysaccharides in industry and medicine. For economic and scientific reasons, large scale production under carefully monitored and controlled conditions is required. Producing exopolysaccharides in industrial fermenters poses several complex bioengineering and microbiological challenges relating primarily to the very high viscosities of such culture media, which are often exacerbated by the producing organism''s morphology. What these problems are, and the strategies for dealing with them are discussed critically in this review, using pullulan, curdlan, xanthan, and fungal ββ-glucans as examples of industrially produced microbial exopolysaccharides. The role of fermenter configuration in their production is also examined. [ABSTRACT FROM AUTHOR]

With intensities 108-1010 times greater than other laboratory sources, X-ray free-electron lasers are currently opening up new frontiers across many areas of science. In this Review we describe how these unconventional lasers work, discuss the range of new sources being developed worldwide, and consider how such X-ray sources may develop over the coming years. [ABSTRACT FROM AUTHOR]

For individuals with muscle invasive bladder cancer, radical cystectomy has remained the gold standard for treatment. Due to the common post operative complaints in patients undergoing radical cystectomy with orthotopic neobladder formation i.e. sexual dysfunction and urinary incontinence, members of the urologic community have sought ways to ameliorate these side effects with prostate and urethra sparing surgery. This review pre-sents that topic based on the contemporary literature regarding the management of the prostate and urethra in men and women undergoing radical cystectomy for muscle invasive bladder cancer. Prostate sparing cystectomy remains controversial. Those in favor of it emphasize sub-stantial improvements in functional outcomes and the effect that it could have on patients' quality of life. Those opposed to it cite increased oncologic risk and violation of the oncologic principle of en bloc excision of at-risk organs. The most current information related to this ongoing debate is presented and discussed. [ABSTRACT FROM AUTHOR]

We tested the hypothesis that endogenously produced hydrogen sulfide (H2S) can potentially contribute to the adrenergic stress response in rainbow trout by initiating catecholamine secretion from chromaffin cells. During acute hypoxia (water P02 = 35 mmHg), plasma H2S levels were significantly elevated concurrently with a rise in circulating catecholamine concentrations. Tissues enriched with chromaffin cells (posterior cardinal vein and anterior kidney) produced H2S in vitro when incubated with L-cysteine. In both tissues, the production of H2S was eliminated by adding the cystathionine β-synthase inhibitor, aminooxyacetate. Cystathionine β-synthase and cystathionine γ-lyase were cloned and sequenced and the results of real-time PCR demonstrated that with the exception of white muscle, mRNA for both enzymes was broadly distributed within the tissues that were examined. Electrical field stimulation of an in situ saline-perfused posterior cardinal vein preparation caused the appearance of H2S and catecholamines in the outfiowing perfusate. Perfusion with the cholinergic receptor agonist carbachol (1 X 10-6 M) or depolarizing levels of KCI (1 X 10-2 M) caused secretion of catecholamines without altering H2S output, suggesting that neuronal excitation is required for H2S release. Addition of H2S (at concentrations exceeding 5 X 10-7 M) to the perfusion fluid resulted in a marked stimulation of catecholamine secretion that was not observed when Ca2+-free perfusate was used. These data, together with the finding that H2S-induced catecholamine secretion was unaltered by the nicotinic receptor blocker hexamethonium, suggest that H2S is able to directly elicit catecholamine secretion via membrane depolarization followed by Ca2+-mediated exocytosis. [ABSTRACT FROM AUTHOR]

Abstract: In the present study, we used a recombinant filamentous fungus strain, Aspergillus niger B1-D, as a model system, and investigated the antioxidant defences in this organism. Our findings indicate that pretreatment with low concentrations of H2O2 completely prevents killing by this oxidant at high concentrations. It shows that A. niger adapts to exposure to H2O2 by reducing growth and inducing a number of antioxidant enzyme activities, including superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, of which the induction of catalase is the most pronounced. Moreover the decline of these antioxidant enzymes activities after H2O2 detoxification, coincides with recommencement of growth. Results from monitoring the extracellular H2O2 concentration clearly indicate a very rapid detoxification rate for H2O2 in adapted A. niger cultures. A mathematical model predicts only very low concentrations of intracellular H2O2 accumulating in such cultures. Our results also show that glutathione plays a role in the oxidative defence against H2O2 in A. niger. On addition of H2O2, the intracellular pool of glutathione increases while the redox state of glutathione becomes more oxidized. [Copyright &y& Elsevier]

Abstract: Attenuated total reflectance mid infrared (ATR-MIR) spectroscopy is a potential technique for the near real-time monitoring of filamentous bioprocesses. Here we investigate the utility of ATR-MIR to monitor and predict concentrations of glycerol and product (clavulanic acid) in a complex antibiotic bioprocess. Streptomyces clavuligerus exhibits filamentous growth, thus, as biomass accumulates the process fluid becomes much more viscous, and develops pronounced non-Newtonian behaviour. A multivariate statistical technique, partial least square (PLS) has been used to develop models for the key analytes over the time course of the bioprocess. These models were then validated externally using unseen samples, not used in the original modelling exercise. Despite the heterogeneous nature of the bioprocess and the resulting complexity of the spectra, the models developed had high correlation coefficient values and low prediction error values of 0.302 and 0.009 for glycerol and clavulanic acid, respectively. The findings extend the use of ATR-MIR in these difficult fluids which are typical of filamentous industrial bioprocesses, and demonstrate the practical utility of the technique in the measurement of a range of analyte types, including those present at relatively modest levels compared to the concentrations of biomass and major substrates. [Copyright &y& Elsevier]

Abstract: Dissolved carbon dioxide is one variable that changes between scales of bioreactor and may thus have a potential influence on the process as scale alters, and especially so in filamentous fungal cultures. The effects of dCO2 on growth and penicillin production by an industrial strain of Penicillium chrysogenum were examined systematically using a steam sterilisable dCO2 probe and a computerized image analysis system. Although low levels of CO2 stimulated growth (increased biomass, lower mean hyphal growth unit (M.H.G.U.) in lag phase) at the expense of antibiotic synthesis, higher levels led to elevated M.H.G.U.''s in the lag phase and were associated with increased clumping and severely reduced penicillin titre. The adverse effects of dCO2 in these cultures were largely mediated by inhibition of growth and substrate uptake in the lag phase, causing morphological changes which might also contribute to reduced penicillin levels. [Copyright &y& Elsevier]

Abstract: Gluconobacter suboxydans was used in the biotransformation of d-sorbitol to l-sorbose, a key step in the industrial manufacture of Vitamin C (ascorbic acid). However, despite evidence of the existence of a range of by-products in the bioprocess, relatively little scientific investigation has focused on the factors influencing by-product formation in this complex bioprocess. The aim of the present study was therefore to investigate systematically the extent of by-product formation in this economically important biotransformation process using batch and continuous cultivation methods and up to date analytical techniques and, thus, to arrive at a realistic assessment of the yield of sorbose via this route. The results presented here show that exogenous by-product addition to shake flask and batch cultures detrimentally affects sorbose production and yield, but can have some positive effects in continuous culture. Some inhibition of fructose accumulation by mannitol-1-phosphate addition was noted in shake flask cultures. [Copyright &y& Elsevier]

An Energy Recovery Linac (ERL) Prototype facility to be built at Daresbury Laboratory serves as a testbed for the study of beam dynamics and accelerator technology important for the design and construction of the 4th Generation Light Source (4GLS). This paper describes the possibility of utilising a planar undulator at the 4GLS prototype facility for the generation of coherent synchrotron radiation in the far infra-red region. [Copyright &y& Elsevier]

Provides information on a study which examines the growth and culturability of Campylobacter jejuni NCTC 11351 and other campylobacters in media having different osmolalities at a range of temperatures. Materials and methods used; Results and discussion.

Focuses on the assessment of the effects of elevated levels of dissolved carbon dioxide (dCO2), produced by gassing with CO2-enriched gas mixtures, upon an industrial strain of Aspergillus niger (strain A60) producing citrate and gluconate. Attention paid to the reliability and accuracy of the steam-sterilizable dCO2; Assessment of the response of the organism to elevated dCO2 levels.

Inflammatory myofibroblastic tumor (IMT) is a tumor of unknown neoplastic potential that rarely arises in the genitourinary tract. We present the case of an otherwise healthy 16-year old boy with gross hematuria who underwent cystoscopy and transurethral resection of the bladder tumor without complication. Biopsy and immunohistochemistry were consistent with anaplastic lymphoma kinase-positive IMT. In addition to presenting this case of IMT, we review presentations, management and prognosis of bladder IMT. [ABSTRACT FROM AUTHOR]

The article reports that the scientists of SLAC National Accelerator Laboratory in Menlo Park, California, have successfully completed a free-electron laser (FEL) facility which can achieve lasing at a wavelength of 1.5 Å. Experts believe that this FEL, the first to operate in the hard X-ray regime, will open up vast new areas for scientific exploration in the field of light-source science. They state that this source will help in study of atomic and molecular science.

The article discusses on the free-electron lasers (FELs) operating at X-ray wavelengths to gather detailed information on how matter interacts and arranges itself at atomic and molecular scales. It states that the output from the FEL is around 108 brighter than current synchrotron sources. The information gathered by the X-ray FELs about molecules, atoms and their electronic states are more efficient than current synchrotron X-ray sources.

An optics-free method is proposed to generate x-ray radiation with spatially variant states of polarization via an afterburner extension to a free electron laser. Control of the polarization in the transverse plane is obtained through the overlap of different coherent transverse light distributions radiated from a bunched electron beam in two consecutive orthogonally polarised undulators. Different transverse profiles are obtained by emitting at a higher harmonic in one or both of the undulators. This method enables the generation of beams structured in their intensity, phase, and polarization—so-called Poincaré beams—at high powers with tunable wavelengths. Simulations are used to demonstrate the generation of two different classes of light with spatially inhomogeneous polarization—cylindrical vector beams and full Poincaré beams. [ABSTRACT FROM AUTHOR]

The article looks at the future prospects in the urine-based markers in bladder cancer. Primarily, the authors discuss selected evolving markers that include survivin, DNA-based methylation assays, c-Met and BLCA-4. They opine that while these markers appear to raise hope, this is tempered by the reality that more studies are necessitated to further validate their effectiveness.

The article informs that the genome sequence of the bacterium Gluconobacter oxydans suggests new ways of harnessing this organism's unusual metabolism for biotechnology. Bacteria of the genus Gluconobacter exhibit so-called oxidative fermentation, or incomplete oxidation, a highly unusual metabolic feature that has been exploited industrially for decades in the production of vitamin C, gluconic acid, etc. The complete genome sequence of Gluconobacter oxydans 621H is reported and with it offer biologists a window into understanding how this unusual microorganism functions and the role of incomplete oxidation in its physiology.

A letter to the editor related to the description of Maxwell?Bloch equations which seems to have developed from a publication by S.L. McCall and E.L. Hahn is presented which was published in the previous issue of the journal.

Background: Among genitourinary malignancies, bladder cancer (BCa) ranks second in both prevalence and cause of death. Biomarkers of BCa for diagnosis, prognosis and disease surveillance could potentially help prevent progression, improve survival rates and reduce health care costs. Among several oncogenic signaling pathways implicated in BCa progression is that of hepatocyte growth factor (HGF) and its cell surface receptor, Met, now targeted by 25 experimental anti-cancer agents in human clinical trials. The involvement of this pathway in several cancers is likely to preclude the use of urinary soluble Met (sMet), which has been correlated with malignancy, for initial BCa screening. However, its potential utility as an aid to disease surveillance and to identify patients likely to benefit from HGF/Met-targeted therapies provide the rationale for this preliminary retrospective study comparing sMet levels between benign conditions and primary BCa, and in BCa cases, between different disease stages.Methods: Normally voided urine samples were collected from patients with BCa (Total: 183; pTa: 55, pTis: 62, pT1: 24, pT2: 42) and without BCa (Total: 83) on tissue-procurement protocols at three institutions and sMet was measured and normalized to urinary creatinine. Normalized sMet values grouped by pathologic stage were compared using non-parametric tests for correlation and significant difference. ROC analyses were used to derive classification models for patients with or without BCa and patients with or without muscle-invasive BCa (MIBCa or NMIBCa).Results: Urinary sMet levels accurately distinguished patients with BCa from those without (p<0.0001, area under the curve (AUC): 0.7008) with limited sensitivity (61%) and moderate specificity (76%), and patients with MIBCa (n=42) from those with NMIBCa (n=141; p<0.0001, AUC: 0.8002) with moderate sensitivity and specificity (76% and 77%, respectively) and low false negative rate (8%).Conclusions: Urinary sMet levels distinguish patients with BCa from those without, and patients with or without MIBCa, suggesting the potential utility of urinary sMet as a BCa biomarker for surveillance following initial treatment. Further studies are warranted to determine its potential value for prognosis in advanced disease, predicting treatment response, or identifying patients likely to benefit from Met-targeted therapies. [ABSTRACT FROM AUTHOR]

Organisms of the genus Gluconobacter have been widely utilized within the biotechnology industry for many decades, due to their unique metabolic characteristics. The metabolic features that render Gluconobacter so useful in biotransformation processes, vitamin synthesis, and, as the biological element in sensor systems, are critically evaluated, and the relevance of recent biochemical genetic studies to current and future industrial Gluconobacter processes is discussed. The impact of recombinant gene technology on the status of Gluconobacter processes and the potential use of such techniques in clarifying aspectsof the physiology of Gluconobacteris reviewed. [ABSTRACT FROM AUTHOR]

Objectives: To assess the utility of genomic testing in risk-stratifying Black patients with low and intermediate risk prostate cancer.Methods: We retrospectively identified 63 Black men deemed eligible for active surveillance based on National Comprehensive Cancer Network (NCCN) guidelines, who underwent OncotypeDx Genomic Prostate Score testing between April 2016 and July 2020. Nonparametric statistical testing was used to compare relevant features between patients reclassified to a higher NCCN risk after genomic testing and those who were not reclassified.Results: The median age was 66 years and median pre-biopsy PSA was 7.3. Initial risk classifications were: very low risk: 7 (11.1%), low risk: 24(38.1%), favorable intermediate risk: 31(49.2%), and unfavorable intermediate risk: 1 (1.6%). Overall, NCCN risk classifications after Genomic Prostate Score testing were significantly higher than initial classifications (P=.003, Wilcoxon signed-rank). Among patients with discordant risk designations, 28(28/40, 70%) were reclassified to a higher NCCN risk after genomic testing. A pre-biopsy prostate specific antigen of greater than 10 did not have significantly higher odds of HBR (OR:2.16 [95% CI: 0.64,7.59, P=.2). Of favorable intermediate risk patients, 20(64.5%) were reclassified to a higher NCCN risk. Ultimately, 18 patients underwent definitive treatment.Conclusions: Incorporation of genomic testing in risk stratifying Black men with low and intermediate-risk prostate cancer resulted in overall higher NCCN risk classifications. Our findings suggest a role for increased utilization of genomic testing in refining risk-stratification within this patient population. These tests may better inform treatment decisions on an individualized basis. [ABSTRACT FROM AUTHOR]

The relationship between prior growth of food-spoilage yeast in high-sugar environments and their subsequent survival postpulsed UV (PUV) irradiation was investigated. Test yeast were separately grown to early stationary phase in YPD broth containing increasing concentrations of glucose (1-50% w/v) and were flashed with ≤40 pulses of broad-spectrum light at lamp discharge energy settings of 3.2, 7.2 and 12.8 J (equivalent to UV doses of 0.53, 1.09 and 3.36 μJ cm−2, respectively) and their inactivation measured. Findings showed that prior growth in high-sugar conditions (≥30% glucose w/v) enhanced the sensitivity of all nine representative strains of Zygosaccharomyces bailii, Z. rouxii and Saccharomyces cerevisiae yeast to PUV irradiation. Significant differences in inactivation amongst different yeast types also occurred depending on amount of UV dose applied, where the order of increasing sensitivity of osmotically stressed yeast to PUV irradiation was shown to be Z. rouxii, Z. bailii and > S. cerevisiae. For example, a 1.2-log order difference in CFU mL−1 reduction occurred between Z. bailii 11 486 and S. cerevisiae 834 when grown in 50% w/v sugar samples and treated with the uppermost test UV dosage of 3.36 μJ cm−2, where these two yeast strains were reduced by 3.8 and 5.0 log orders, respectively, after this PUV treatment regime compared to untreated controls. The higher the UV dose applied the greater the reduction in yeast numbers. For example, a 1.0-, 1.4- and 4.0-log order differences in CFU mL−1 numbers occurred for S. cerevisiae 834 grown in 15% w/v sugar samples and then treated with PUV dose of 0.53, 1.09 and 3.36 μJ cm−2, respectively. These findings support the development of PUV for the treatment of high-sugar foods that are prone to spoilage by osmotolerant yeast. [ABSTRACT FROM AUTHOR]

Abstract: Despite the importance of filamentous fungi in the biotechnology industry, little is known about their metabolism under the stressful conditions experienced in typical production fermenters. In the present study, oxygen enrichment was used to recreate an industrial batch process, and the effects of the increasing dissolved oxygen tension were studied as regards the cellular metabolism. It was found that elevated dissolved oxygen tension led to an oxidatively stressful environment, as detailed by rapid initial increases in reactive oxygen species (ROS) concentrations and antioxidant enzyme activities. Intracellular protein concentrations also decreased in oxygenated cultures; this appeared to be concomitant with a decrease in the adenosine-5′-triphosphate (ATP) pool in these cultures. Oxygenated cultures showed early senescence and death compared to aerated control cultures. Despite earlier studies proposing various mechanisms for such findings in fungal cultures subjected to oxidative stress, these findings can best be explained by the fact that in such cultures the activity of alternative NADH dehydrogenases was significantly increased, which served to maintain lower ROS concentrations throughout the duration of the process but in doing so also reduced the ability of the organism to create a proton motive force by which to drive ATP synthesis. The findings of the present study help further our understanding of the central roles of these highly conserved enzymes within fungal metabolism under oxidative stress. [Copyright &y& Elsevier]

Fungi are amongst the most industrially important microorganisms in current use within the biotechnology industry. Most such fungal cultures are highly aerobic in nature, a character that has been frequently referred to in both reactor design and fungal physiology. The most fundamentally significant outcome of the highly aerobic growth environment in fermenter vessels is the need for the fungal culture to effectively combat in the intracellular environment the negative consequences of high oxygen transfer rates. The use of oxygen as the respiratory substrate is frequently reported to lead to the development of oxidative stress, mainly due to oxygen-derived free radicals, which are collectively termed as reactive oxygen species (ROS). Recently, there has been extensive research on the occurrence, extent, and consequences of oxidative stress in microorganisms, and the underlying mechanisms through which cells prevent and repair the damage caused by ROS. In the present study, we critically review the current understanding of oxidative stress events in industrially relevant fungi. The review first describes the current state of knowledge of ROS concisely, and then the various antioxidant strategies employed by fungal cells to counteract the deleterious effects, together with their implications in fungal bioprocessing are also discussed. Finally, some recommendations for further research are made. [ABSTRACT FROM AUTHOR]

Abstract: Thermophilic aerobic digestion (TAD) of heteroxylan waste was implemented at waste load of 30gL−1 with mineral nitrogen supplementation to study effect of the process on waste degradation, protein accretion and quality. Digestions were carried out at 45 50, 55, 60 and 65°C using Bacillus stearothermophilus in a CSTR under batch conditions at 1.0vvm aeration rate, pH 7.0 for a maximum of 120h. Amylase and xylanase activities appeared rapidly in the digest, while basal protease activity appeared early in the digestion and increased towards end of the processes. Highest degradation of volatile suspended solid, hemicellulose and fibre occurred at 55°C while highest degradation of total suspended solid occurred at 60°C. Highest protein accretion (258.8%) and assimilation of mineral nitrogen and soluble protein occurred at 55°C. The % content of amino acids of digest crude protein increased relative to raw waste and with digestion temperature. Quality of digest protein was comparable to the FAO standard for feed use. TAD has potentials for use in the protein enrichment of waste. [Copyright &y& Elsevier]

Abstract: It is now accepted that heat treatment can lead to oxidative stress events in microorganisms, but there are few detailed studies on protein oxidation and consequent recycling/elimination of oxidatively damaged proteins following such heat treatment. In batch cultures of a filamentous fungus, Aspergillus niger B1-D, raising culture temperature from 25°C to 30°C and 35°C led to a general enhancement of intracellular metabolism, a higher specific growth rate, increased consumption of carbon and nitrogen sources, and raised intracellular ATP content in the exponential phase. By contrast, there was a transient accumulation of protein carbonyls, a widely used biomarker of protein oxidation, following such temperature increases, which could indicate that cellular antioxidant defences were being temporarily overwhelmed under these circumstances, despite the fact that enhanced activities in antioxidant enzyme activities have been reported in microorganisms during such heat treatment. Protein carbonyls can only be removed by proteolysis. The intracellular proteolytic activity in batch cultures of A. niger was found generally enhanced by temperature elevation, suggesting the role of proteolytic activity in protein quality control during heat treatment was dependant on the culture temperature. [Copyright &y& Elsevier]

Abstract: Filamentous fungi are industrially important organisms because of their ability to produce secondary metabolites, and as expression systems for heterologous proteins. Since secretion of secondary metabolites in filamentous fungi is associated with the older, more vacuolated parts of the hyphae culture morphology is a crucial reflection of their physiology in submerged cultures. Therefore, any factor affecting fungal morphology will in turn affect secondary metabolite production. In this study we examine and report the effects of elevated levels of the potent morphogen, carbon dioxide upon morphology and antibiotic production in an industrially important fungal system. The effects of elevated CO2 levels on cephalosporin C (CPC) production, metabolic performance and morphological changes in batch cultures of Acremonium chrysogenum (ATCC 48272) were investigated. High levels of dCO2 led to reduction of CPC production by up to 36%. Both metabolic activity and substrate uptake were severely inhibited by elevated CO2, especially at 15 and 20% CO2. Both micro and macromorphology of A. chrysogenum were profoundly changed in bioprocesses sparged with CO2 especially at high levels, and these changes were a contributory cause of the reduction in CPC production. [Copyright &y& Elsevier]

Abstract: Oxygen enrichment (sparging bioreactors with oxygen-enriched air) ameliorates oxygen limitation in batch cultures of Aspergillus niger B1-D, and although nutrient utilization rates for both the carbon source and the nitrogen source are higher in oxygen-enriched cultures, excess oxygen does not enhance specific growth rate, instead the “extra” nutrient consumption is associated with defensive measures. Commencement of oxygen enrichment in early exponential phase leads to a transient rise in proteins showing oxidative damage (carbonylation), and to induction of enhanced proteolytic activity, which points to the antioxidant defense being temporarily overwhelmed, and that A. niger adapts to this oxidative environment by enhancing intracellular proteolytic activity to degrade damaged proteins which might otherwise accumulate under these conditions. Also the energy status of A. niger, reflected by intracellular ATP content, is found to be altered upon the commencement of oxygen enrichment and then reaches much lower levels than in the control. The reasons underlying this are discussed in the context of what is known regarding alternative respiration in industrial fungi. [Copyright &y& Elsevier]

Although host proteases are often considered to have a negative impact upon heterologous protein production by filamentous fungi, relatively little is known about the pattern of their appearance in recombinant fungal bioprocesses. In the present study, we investigated extracellular proteases from a filamentous fungus, Aspergillus niger B1-D, genetically modified to secrete hen egg white lysozyme (HEWL). Our findings indicate that extracellular protease activity is only detected after the carbon source is completely utilised in batch cultures. The proteases are predominantly acid proteases and have optimal temperature for activity at around 45°C. Their activity could be partially inhibited by protease inhibitors, indicating the existence of at least four kinds of proteases in these culture fluids, aspartic-, serine-, cysteine-, and metallo-proteases. Oxygen enrichment does not have any noticeable effects on extracellular protease activity except that the onset of protease activity appears earlier in oxygen enrichment runs. Oxygen enrichment stimulates HEWL production substantially, and we propose that it is related to fungal morphology. Thermal stress imposed by raising process temperature (from 25 to 30 and 35°C) in early exponential phase, led to appearance of protease activity in the medium following the heat shock. Continued cultivation at high temperatures significantly reduced HEWL production, which was associated with increased activity of the extracellular proteases in these cultures. [ABSTRACT FROM AUTHOR]

Abstract: Maca (Lepidium meyenii walp.), a biennial herbaceous plant of the family Brassicae, which is cultivated mainly in the central Andes of Peru, has been used as both a food and a traditional medicine in the region for over 2000 years. The subterranean parts of the plant have long been used as a staple foodstuff by indigenous peoples in the Andean region, but the plant is also valued for its medicinal role. As is usual with many traditional “folk” medicines, many claims have been made regarding the efficacy of maca in treating a wide range of illnesses and medical conditions. However, in the 20th century most scientific attention has been focused in the areas where the pharmacological actions of maca seem most strongly attested, these include, enhancement of sexual drive in humans, increasing overall vigour and energy levels, and increasing sexual fertility in humans and domestic livestock. Since the early days of the 20th century numerous scientific studies have been carried out into the basis of its pharmacological action in these areas. In this review, the composition and pharmacological function of maca are systematically discussed. Additionally, the current discussion surrounding its mode of action in the areas listed above is also presented. [Copyright &y& Elsevier]

Abstract: The application of near infrared spectroscopy in bioprocessing has been limited by its dependence on calibrations derived from single bioreactor at a given time. Here, we propose a multiplexed calibration technique which allows calibrations to be built from multiple bioreactors run in parallel. This gives the flexibility to monitor multiple vessels and facilitates calibration model transfer between bioreactors. Models have been developed for the two key analytes: glucose and lactate using Chinese hamster ovary (CHO) cell lines and using analyte specific information obtained from the feasibility studies. We observe slight model degradation for the multiplexed models in comparison to the conventional (single probe) models, decrease in r 2 values from 89.4% to 88% for glucose whereas for lactate from 92% to 91.8% and a simultaneous increase in the number of factors as the model incorporates the inter-probe variability, nevertheless the models were fit for purpose. The results of this particular application of implementing multiplexed-NIRS to monitor multiple bioreactor vessels are very encouraging, as successful models have been built on-line and validated externally, which proffers the prospect of reducing timelines in monitoring the vessels considerably, and in turn, providing improved control. [Copyright &y& Elsevier]

Abstract: The need for effective bioprocess (fermentation) monitoring is growing in importance due to the rapid pace of change in the fermentation industry, and attendant financial pressures. Vibrational spectroscopy has shown great promise in bioprocess monitoring. In particular, recently attention has been focused on the capability of mid infrared spectroscopy (MIRS) to monitor multiple analytes in highly complex fermentation fluids. The potential of this powerful analytical technique is critically evaluated by discussion of relevant studies. The advantages and limitations of MIR are discussed in the context of “rival” technologies, such as near infrared, focusing especially on employing such techniques in bioprocesses for real time (either in situ or ex situ) measurements. The potential barriers to the development of MIRS for real time monitoring are identified and further research directions highlighted. [Copyright &y& Elsevier]

Abstract: The utility of attenuated total reflectance-mid-infrared spectroscopy (ATR-MIR) to monitor the concentrations of the key analytes ammonium, glucose, methyl oleate and biomass in a Streptomyces clavuligerus bioprocess for the synthesis of clavulanic acid was investigated. The cultivation medium was complex and the process fluid (matrix) underwent profound changes as culture growth proceeded, representing a considerable challenge from a spectroscopic viewpoint. Quantitative models were developed using the multivariate statistical technique, partial least square (PLS) for the key analytes over the entire time course of the bioprocess, which were validated externally using samples not incorporated in the original modelling exercise. The reasoning behind the choice of modelling strategy for each analyte is discussed, with particular focus on biomass modelling in order to generate clearer insight into the modelling process in this complex matrix. Despite the heterogeneous nature of the sample matrix, and the complexity of the spectral information arising, at-line models were developed giving low prediction error values for the analytes: ammonium 0.013g/l; glucose 0.56g/l; methyl oleate 0.38g/l and biomass 0.39g/l, respectively. These findings represent a considerable advance on previous studies using NIR in antibiotic processes, as all key analytes have been successfully modelled here, and the use of ATR-MIR in complex bioprocess fluids has been shown to be a viable method of near real-time monitoring. [Copyright &y& Elsevier]

Abstract: The effects of agitation and aeration upon synthesis and molecular weight of the biopolymer gellan were systematically investigated in batch fermenter cultures of the bacterium, Sphingomonas paucimobilis. High aeration rates and vigorous agitation enhanced growth of S. paucimobilis. Although gellan formation occurred mainly in parallel with cell growth, the increase in cells able to synthesise gellan did not always lead to high gellan production. For example, at very high agitation rates (1000rpm) growth was stimulated at the expense of biopolymer synthesis. Maximal gellan concentration was obtained at 500rpm agitation and either 1 or 2vvm aeration (12.3 and 12.4g/l gellan, respectively). An increase in aeration (from 1 to 2vvm) enhanced gellan synthesis only at low agitation rates (250rpm). However, high aeration or dissolved oxygen was not necessary for high gellan synthesis, in fact oxygen limitation always preceded the phase of maximum gellan production and probably enhanced polysaccharide biosynthesis. Some gellan was formed even after glucose exhaustion. This was attributed to the intracellular accumulation of polyhydroxyalkanoates, (such as polyxydroxybutyrate) which were found in S. paucimobilis cells indicating the existence of a carbon storage system, which may contribute to gellan biosynthesis under glucose-limiting conditions. The autolysis of the culture, which occurred at the late stages of the process, seemed to be triggered mainly by limitations in mass (nutrient) transfer, due to the highly viscous process fluid that gradually develops. Rheological measurements generally gave a very good near real time estimate of maximum biopolymer concentration offering the possibility of improved process control relative to time consuming gravimetric assay methods. While mechanical depolymerisation of gellan did not occur, high aeration rates (2vvm) led to production of gellan of low molecular weight (at either 250 or 500rpm). This effect of aeration rate upon gellan molecular weight is reported here for the first time, and is important for the properties and applications of gellan. Mechanisms which may have led to this are discussed, but control of molecular weight of the biopolymers is clearly an area needing further research. [Copyright &y& Elsevier]

Thermophilic aerobic digestion (TAD) of a model agricultural waste slurry was carried out in a continuously stirred tank reactor for a total of 156 h at 55 °C. The pH of the digestion was either unregulated or regulated at 6.0, 7.0, 8.0, 9.0 and 9.5 at 0.5 volume of air per volume of waste slurry per minute (vvm) aeration rate. The effect of aeration rate was studied at 0.1, 0.25, 0.5 and 1.0 vvm at pH 7.0. Development of thermophilic populations and amylase and cellulase enzyme activities in the digesting slurry were studied. Thermophiles developed rapidly to reach peak populations in 24 h or earlier. After 96 h, thermophiles were present mostly as spores. They were only slightly affected by aeration rate, but more by digestion pH. Amylase developed rapidly to reach peak activity before declining as rapidly. activity Cellulase was considerably affected by aeration rate but not digestion pH. Amylase profile closely reflected development of microbial activity, and so the progress of TAD. It may be useful as a control tool, either alone or in combination with other process data, for monitoring the TAD of complex waste slurries. [Copyright &y& Elsevier]

It has been known for many years that oxygen (O2) may have toxic effects on aerobically growing microorganisms, mainly due to the threat arising from reactive oxygen species (ROS). In submerged culture industrial fermentation processes, maintenance of adequate levels of O2 (usually measured as dissolved oxygen tension (DOT)) can often be critical to the success of the manufacturing process. In viscous cultures of filamentous cultures, actively respiring, supplying adequate levels of O2 to the cultures by conventional air sparging is difficult and various strategies have been adopted to improve or enhance O2 transfer. However, adoption of those strategies to maintain adequate levels of DOT, that is, to avoid O2 limitation, may expose the fungi to potential oxidative damage caused by enhanced flux through the respiratory system. In the past, there have been numerous studies investigating the effects of DOT on fungal bioprocesses. Generally, in these studies moderately enhanced levels of O2 supply resulted in improvement in growth, product formation and acceptable morphological changes, while the negative impact of higher levels of DOT on morphology and product synthesis were generally assumed to be a consequence of "oxidative stress." However, very little research has actually been focused on investigation of this implicit link, and the mechanisms by which such effects might be mediated within industrial fungal processes. To elucidate this neglected topic, this review first surveys the basic knowledge of the chemistry of ROS, defensive systems in fungi and the effects of DOT on fungal growth, metabolism and morphology. The physiological responses of fungal cells to oxidative stress imposed by artificial and endogenous stressors are then critically reviewed. It is clear that fungi have a range of methods available to minimize the negative impacts of elevated ROS, but also that development of the... [ABSTRACT FROM AUTHOR]

Continuous chemostat cultures of a recombinant strain of Aspergillus niger (B1-D), engineered to produce the marker protein hen egg white lysozyme, were investigated with regard to their susceptibility to oxidative stress. The culture response to oxidative stress, produced either by addition of exogenous hydrogen peroxide (H2O2) or by high dissolved oxygen tension (DOT), was characterised in terms of the activities of two key defensive enzymes: catalase (CAT) and superoxide dismutase (SOD). Since the morphology is so critical in submerged fungal bioprocesses, the key morphological indices were analysed using a semi-automated image analysis system. Both oxidant stressors, H2O2 and elevated DOT, increased both enzyme activities, however, the extent was different: exogenous H2O2 led mainly to increased CAT activity, whereas gassing with O2 enriched air, which resulted in a DOT of 165% of air saturation, increased both enzyme activities more than 2-fold compared with the control steady state culture. Addition of exogenous H2O2 resulted in shorter hyphae compared with control steady state cultures. These findings indicate that it is unsound to use exogenous H2O2 to simulate oxidative stress induced by elevated dissolved oxygen levels since the response to each might be quite different, both in terms of enzymatic (defensive) responses and in terms of culture morphology. [Copyright &y& Elsevier]

A recombinant strain of Aspergillus niger (B1-D), engineered to produce the marker protein hen egg white lysozyme (HEWL), was investigated with regard to its susceptibility to oxidative stress. The culture response to oxidative stress, produced either by menadione (MD) or by H2O2, was characterised in terms of the intracellular activities of two key defensive enzymes, catalase (CAT) and superoxide dismutase (SOD), in the presence or absence of a range of vitamin supplements.Addition of either ascorbate (Vit C) or α-tocopherol (Vit E) resulted in different responses of A. niger cultures to exogenous H2O2 (1 mM). In the presence of Vit C the activity of SOD was increased by 50% compared to control cultures, whereas incorporation of Vit E appeared to have a “protective” effect against reactive oxygen species (ROS).Continuous addition of menadione (1.2 mmole l−1 h−1) to submerged cultures of A. niger in the bioreactor resulted in an increase of CAT and SOD activities during the exponential phase of growth, whereas enzyme levels remained almost constant during that phase in control cultures. Comparison of these results with the response to oxidative stress caused by addition of exogenous H2O2 and elevated dissolved oxygen tension (DOT) shows that these three stressors are quite distinct. [Copyright &y& Elsevier]