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PRÜFUNG UND QUALITÄT VON MIKROBIELLEN PRODUKTEN - EINLEITENDE BEMERKUNGEN
No full textDas Ziel, wenn auch sicher nicht das einzige Resultat der Entwicklung
neuer mikrobieller Verfahren zur Proteingewinnung sind Futtermittel und
Nahrungsmittel. Es ist ein uralter und sehr erfolgreicher Trick in der
Evolution, seine Ernährungsbasis durch Bakterien und deren Metaboliten
zu verbessern. Nicht nur bei Wiederkäuern - ein großer Teil des Milchproteins,
das wir verzehren, ist bakteriellen Ursprungs -, auch z.B.
bei Kaninchen und sogar bei manchen Primaten
POTATO: Automated pipeline for batch analysis of optical tweezers data
No full textOptical tweezers are a single-molecule technique that allows probing of intra- and intermolecular interactions that govern complex biological processes involving molecular motors, protein-nucleic acid interactions, and protein/RNA folding. Recent developments in instrumentation eased and accelerated optical tweezers data acquisition, but analysis of the data remains challenging. Here, to enable high-throughput data analysis, we developed an automated python-based analysis pipeline called POTATO (practical optical tweezers analysis tool). POTATO automatically processes the high-frequency raw data generated by force-ramp experiments and identifies (un)folding events using predefined parameters. After segmentation of the force-distance trajectories at the identified (un)folding events, sections of the curve can be fitted independently to a worm-like chain and freely jointed chain models, and the work applied on the molecule can be calculated by numerical integration. Furthermore, the tool allows plotting of constant force data and fitting of the Gaussian distance distribution over time. All these features are wrapped in a user-friendly graphical interface, which allows researchers without programming knowledge to perform sophisticated data analysis.Optical tweezers are a single-molecule technique that allows probing of intra- and intermolecular interactions that govern complex biological processes involving molecular motors, protein-nucleic acid interactions, and protein/RNA folding. Recent developments in instrumentation eased and accelerated optical tweezers data acquisition, but analysis of the data remains challenging. Here, to enable high-throughput data analysis, we developed an automated python-based analysis pipeline called POTATO (practical optical tweezers analysis tool). POTATO automatically processes the high-frequency raw data generated by force-ramp experiments and identifies (un)folding events using predefined parameters. After segmentation of the force-distance trajectories at the identified (un)folding events, sections of the curve can be fitted independently to a worm-like chain and freely jointed chain models, and the work applied on the molecule can be calculated by numerical integration. Furthermore, the tool allows plotting of constant force data and fitting of the Gaussian distance distribution over time. All these features are wrapped in a user-friendly graphical interface, which allows researchers without programming knowledge to perform sophisticated data analysis. -(c) 2022 Biophysical SocietyEuropean Research Council:
The work in our laboratory is supported by the Helmholtz
Association and grants from the European Research Council (ERC) Grant Nr. 94863
Unsaturated Fatty Acids Control Biofilm Formation of Staphylococcus aureus and Other Gram-Positive Bacteria.
No full textInfections involving biofilms are difficult to treat due to increased resistances against antibiotics and the immune system. Hence, there is an urgent demand for novel drugs against biofilm infections. During our search for novel biofilm inhibitors from fungi, we isolated linoleic acid from the ascomycete Hypoxylon fragiforme which showed biofilm inhibition of several bacteria at sub-MIC concentrations. Many fatty acids possess antimicrobial activities, but their minimum inhibitory concentrations (MIC) are high and reports on biofilm interferences are scarce. We demonstrated that not only linoleic acid but several unsaturated long-chain fatty acids inhibited biofilms at sub-MIC concentrations. The antibiofilm activity exerted by long-chain fatty acids was mainly against Gram-positive bacteria, especially against Staphylococcus aureus. Micrographs of treated S. aureus biofilms revealed a reduction in the extracellular polymeric substances, pointing to a possible mode of action of fatty acids on S. aureus biofilms. The fatty acids had a strong species specificity. Poly-unsaturated fatty acids had higher activities than saturated ones, but no obvious rule could be found for the optimal length and desaturation for maximal activity. As free fatty acids are non-toxic and ubiquitous in food, they may offer a novel tool, especially in combination with antibiotics, for the control of biofilm infections
Blastopirellula retiformator sp. nov. isolated from the shallow-sea hydrothermal vent system close to Panarea Island.
No full textAquatic bacteria belonging to the deep-branching phylum Planctomycetes play a major role in global carbon and nitrogen cycles. However, their uncommon morphology and physiology, and their roles and survival on biotic surfaces in marine environments, are only partially understood. Access to axenic cultures of different planctomycetal genera is key to study their complex lifestyles, uncommon cell biology and primary and secondary metabolism in more detail. Here, we describe the characterisation of strain Enr8T isolated from a marine biotic surface in the seawater close to the shallow-sea hydrothermal vent system off Panarea Island, an area with high temperature and pH gradients, and high availability of different sulphur and nitrogen sources resulting in a great microbial diversity. Strain Enr8T showed typical planctomycetal traits such as division by polar budding, aggregate formation and presence of fimbriae and crateriform structures. Growth was observed at ranges of 15-33 °C (optimum 30 °C), pH 6.0-8.0 (optimum 7.0) and at NaCl concentrations from 100 to 1200 mM (optimum 350-700 mM). Strain Enr8T forms white colonies on solid medium and white flakes in liquid culture. Its genome has a size of 6.20 Mb and a G + C content of 59.2%. Phylogenetically, the strain belongs to the genus Blastopirellula. We propose the name Blastopirellula retiformator sp. nov. for the novel species, represented by the type strain Enr8T (DSM 100415T = LMG 29081T)
Rhodopirellula heiligendammensis sp. nov., Rhodopirellula pilleata sp. nov., and Rhodopirellula solitaria sp. nov. isolated from natural or artificial marine surfaces in Northern Germany and California, USA, and emended description of the genus Rhodopirellula.
No full textExpanding the collection of Planctomycetes by characterisation of novel species is key to better understanding of their complex lifestyles, uncommon cell biology and unexplored metabolism. Here, we isolated three novel planctomycetal strains from a kelp forest on the California Coastline at Monterey Bay or from plastic surfaces submerged in the Baltic Sea and the estuary of the river Warnow in the northeast of Germany. According to our phylogenetic analysis, the isolated strains Poly21T, Pla100T and CA85T represent three novel species within the genus Rhodopirellula. All three show typical planctomycetal traits such as division by budding. All are aerobic, mesophilic chemoheterotrophs and show genomic features comparable to other described Rhodopirellula species. However, strain CA85T is exceptional as it forms cream colonies, but no aggregates, which is a notable deviation from the pink- to red-pigmented and aggregate-forming Rhodopirellula species known thus far. We propose the names Rhodopirellula heiligendammensis sp. nov., Rhodopirellula pilleata sp. nov., and Rhodopirellula solitaria sp. nov. for the novel strains Poly21T (DSM 102266T = LMG 29467T = CECT 9847T = VKM B-3435T), Pla100T (DSM 102937T = LMG 29465T) and CA85T (DSM 109595T = LMG 29699T = VKM B-3451T), respectively, which we present as the respective type strains of these novel species
Dual-function chromogenic screening-based CRISPR/Cas9 genome editing system for actinomycetes.
No full textON-LINE ANALYSIS AND CONTROL OF FERMENTATION PROCESSES
No full textThis paper gives a brief account on the results using mini-computer for on-line,
real-time followup and control of fermentation processes.
Data indicate that the status of a microbiol culture can be characterized if the available
direct sensor signals are further analyzed. Such an analysis gives insight into the
physico-chemical, physiological and biochemical conditions of the culture. In particular,
the gas exchange conditions (oxygen uptake, CO? release rates and
especially respiratory quotient (RQ)) were found sensitive indicators of the
culture's status.
Using the process status analysis capability of the computer optimum environmental
conditions were searched by means of perturbation testing of the culture. For
example, a C/N ratio was found in C. utilis culture which resulted in near perfect
oxidation (RQ close to 1.0) which coincided with enhanced cell growth rate and
suppressed ethyl alcohol formation. During these tests interactions between the
environmental factors and the cellular metabolism were also detected. Analysis
of these interactions is a prerequisite to develop control techniques for microbiological
processes.
Information on the interactions between the cells and environment as well as on
the process status made it possible to establish a culture milieu in which the
C. utilis cells metabolism was shifted in the direction of protein synthesis with simultaneous decrease in ETOH production. This operation was implemented
using a double control loop strategy in which the setpoints of the individual
controlled variables (composite of which creates the environment) were adjusted
according to the physiological state of the culture
TOXICOLOGICAL TESTING OF SCP, 1975, 1980 AND 1985
No full textWide experience with the testing of Single Cell Protein
(SCP) during the last decade has not provided obstacles to
the development of these materials.
Initial tests with SCP produced abnormal reactions with
humans. It is generally seen that the best application for
SCP lies in the field of animal nutrition. No major
toxicological problems have been seen in a wide variety of
animals. The abnormalities noted are mainly nutritional in
origin, and stem from the difficulties associated with the
toxicological testing methods for major nutrient
ingredients. As a result of these experiments and the
experience gained it is considered likely that the extent of
testing required in the future will gradually reduce and
that SCP will become accepted as a normal commercial feed
material
GEWINNUNG MIKROBIELLER BIOMASSE ALS NEBENPRODUKT DER ABWASSERBEHANDLUNG IN ALGENGRÄBEN
No full textIn the course of an Israeli-German Project concerning photosynthetic treatment of
domestic sewage the "Intensive Algal Wastewater Treatment System (IAWIS)" was
developed from existing high-rate pond technology. An IAWIS demonstration plant
near Haifa was operated for several years, rendering effluent of high quality.
Several tons of algae-bacteria biomass were recovered as a byproduct containing
about 50 % of crude protein. Extended feeding tests and toxicological studies in
animals proved the microbial biomass to be a suitable feed ingredient.
Experiments with high-rate sewage oxidation ponds in the Federal Republic of
Germany concerned the treatment of the liquid phase of piggery waste. The removal
of BOD, , N and P was efficient, proceeding, however, at lower rate in winter,
especially with respect to P removal rate.
In order to conserve energy, concentrated liquid wastes should rather be treated
by anaerobic/aerobic multistage processes in which high-rate oxidation ponds may
be used as the aerobic step. Excess quantities of liquid manure are suggested as
target substrates. Improved removal of COD is one of the aims of ongoing studies
Inhibition of MCL1 induces apoptosis in anaplastic large cell lymphoma and in primary effusion lymphoma.
No full textOverexpression of antiapoptotic BCL2 family proteins occurs in various hematologic malignancies and contributes to tumorigenesis by inhibiting the apoptotic machinery of the cells. Antagonizing BH3 mimetics provide an option for medication, with venetoclax as the first drug applied for chronic lymphocytic leukemia and for acute myeloid leukemia. To find additional hematologic entities with ectopic expression of BCL2 family members, we performed expression screening of cell lines applying the LL-100 panel. Anaplastic large cell lymphoma (ALCL) and primary effusion lymphoma (PEL), 2/22 entities covered by this panel, stood out by high expression of MCL1 and low expression of BCL2. The MCL1 inhibitor AZD-5991 induced apoptosis in cell lines from both malignancies, suggesting that this BH3 mimetic might be efficient as drug for these diseases. The ALCL cell lines also expressed BCLXL and BCL2A1, both contributing to survival of the cells. The combination of specific BH3 mimetics yielded synergistic effects, pointing to a novel strategy for the treatment of ALCL. The PI3K/mTOR inhibitor BEZ-235 could also efficiently be applied in combination with AZD-5991, offering an alternative to avoid thrombocytopenia which is associated with the use of BCLXL inhibitors