47 research outputs found
Alternative strategies to by-pass the plant-based Azadirachtin-A production
All parts of Neem (Azadirachta indica A. Juss) show a broad spectrum efficacy against insect pests including insecticidal, anti-feedant or insect repellent activities. Several studies have shown that plant cell cultures can produce azadirachtins. We induced more than 40 novel Neem cell lines in modified Murashige and Skoog (MS) media containing different concentrations of auxins and cytokinins. To enhance the Azadirachtin production from 1 mg/l, it was necessary to optimize the media composition separately for biomass and secondary metabolite production. In light of this complex challenge we used our novel fully automated high-throughput microbioreactor system that allows us a fast and controlled batch and fedbatch screening in 48-well microtiter plates. There is increasing evidence that plants like Azadirachta indica contain endophytes which are able to colonize internal plant tissue without causing visible disease symptoms. The estimated high species diversity of endophytes suggests a rich and almost untapped source of new secondary metabolites. We isolated more than 340 endophytes from various plant tissues and tested if they were able to produce Azadirachtin-A. Here, we present data on isolation of endophytes and induction of callus as well as first results of our microbioreactor system
The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study
AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease
Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study
Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
Silica Hydrogels as Entrapment Material for Microalgae
Despite being a promising feedstock for food, feed, chemicals, and biofuels, microalgal production processes are still uneconomical due to slow growth rates, costly media, problematic downstreaming processes, and rather low cell densities. Immobilization via entrapment constitutes a promising tool to overcome these drawbacks of microalgal production and enables continuous processes with protection against shear forces and contaminations. In contrast to biopolymer gels, inorganic silica hydrogels are highly transparent and chemically, mechanically, thermally, and biologically stable. Since the first report on entrapment of living cells in silica hydrogels in 1989, efforts were made to increase the biocompatibility by omitting organic solvents during hydrolysis, removing toxic by-products, and replacing detrimental mineral acids or bases for pH adjustment. Furthermore, methods were developed to decrease the stiffness in order to enable proliferation of entrapped cells. This review aims to provide an overview of studied entrapment methods in silica hydrogels, specifically for rather sensitive microalgae
Encapsulated Metarhizium brunneum Hyphae for Biological Crop Protection
Krell V, Jakobs-Schönwandt D, Patel A. Encapsulated Metarhizium brunneum Hyphae for Biological Crop Protection. In: Special Issue: ProcessNet‐Jahrestagung und 32. DECHEMA‐Jahrestagung der Biotechnologen 2016. Chemie Ingenieur Technik. Vol 88. Wiley; 2016: 1374-1374
Bioprocess Engineering to Improve Metarhizium brunneum Shelf Life
Krell V, Jakobs-Schönwandt D, Patel A. Bioprocess Engineering to Improve Metarhizium brunneum Shelf Life. In: Special Issue: ProcessNet‐Jahrestagung und 32. DECHEMA‐Jahrestagung der Biotechnologen 2016. Chemie Ingenieur Technik. Vol 88. Wiley; 2016: 1369-1369
Unraveling the interaction of co-encapsulated Saccharomyces cerevisiae and Metarhizium brunneum in calcium alginate-based attract-and-kill beads
Hermann KM, Grünberger A, Patel AV. Unraveling the interaction of co-encapsulated Saccharomyces cerevisiae and Metarhizium brunneum in calcium alginate-based attract-and-kill beads. Pest Management Science. 2024.BACKGROUND: Attract-and-kill (AK) beads are biological, microbial insecticides developed as an alternative to synthetic soil insecticides. For wireworm control, beads are based on calcium alginate/starch co-encapsulating the carbon dioxide (CO2) producing yeast Saccharomyces cerevisiae H205 as the attract component, and the entomopathogenic fungus Metarhizium brunneum CB15-III as the kill component. However, the physicochemical processes inside beads during co-cultivation are still unclear. Here we reveal for the first time the spatiotemporal conditions of oxygen and pH inside AK beads measured with microelectrodes and describe the impact of S. cerevisiae on CO2 and conidia formation.; RESULTS: Measurements revealed a steep oxygen gradient already 2days after co-encapsulation, with an internal hypoxic zone. Encapsulating either S. cerevisiae or M. brunneum already decreased the average pH from 5.5 to 4.7 and 4.6, respectively. However, on day 3, co-cultivation lead to temporal strong acidification of beads down to pH3.6 which followed the maximum CO2 productivity and coincided with the maximum conidiation rate. Decreasing the yeast load decreased the total CO2 productivity to half, and the conidial production by 93%, while specific productivities normalized to 1% yeast load increased eight-fold and three-fold, respectively, with day 3 being an exception.; CONCLUSION: Our findings indicate a general beneficial interaction between M. brunneum and S. cerevisiae, but also suggest competition for resources. These findings will contribute to develop innovative co-formulations with maximum efficiency to save application rates and costs. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry
Verkapselung eines nematophagen Pilzes in einem neuartigen Hohlkugeltyp zur biologischen Nematodenbekämpfung
Patel A, Rose T, Gutberlet V, Müller J, Vorlop K-D. Verkapselung eines nematophagen Pilzes in einem neuartigen Hohlkugeltyp zur biologischen Nematodenbekämpfung. In: Chemie Ingenieur Technik. Chemie Ingenieur Technik. Vol 74. Wiley; 2002: 686-687
Increased neem extract content enhances drying survival of co-encapsulated <i>Saccharomyces cerevisiae</i> and decreases relative release of azadirachtin
<p>Plant extracts from the neem tree can be applied as a bioinsecticidal compound in ‘attract-and-kill’ co-formulations to control soil-dwelling insect pests. Since insects are attracted to the bioinsecticide, the attract-and-kill approach benefits from a reduced dose of insecticide needed. Here, we demonstrate that a powdery neem seed kernel extract in combination with corn starch significantly enhances the drying survival of co-encapsulated CO<sub>2</sub>-releasing <i>Saccharomyces cerevisiae</i>. Additionally, an increased content of the neem extract was shown to slow down the relative release of azadirachtin A. Both findings are of high relevance for the development of formulations in the field of biological pest control.</p