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Considering the recurrence of Pectinatus in breweries, detection and differentiation of contaminating isolates is important for quality control to mitigate recurring or newly developed spoilage pro...

Brewery filling equipment is continually exposed to moisture and nutrients during production runs and is therefore susceptible to microbial attachment and biofilm development. These biofilms play the role of reservoirs of beer spoilage microorganisms. We evaluated the usability of matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis for direct identification of beer contaminants and direct analysis of biofilm. From a total of 58 isolates obtained from the beer filling hall environment, 47% were successfully assigned to the species level and 10% to the genus level when using the commercially available BioTyper (Bruker Daltonik) database. After homemade extension of the database by eight entries belonging to genera Pectinatus, Megasphaera, and Selenomonas, the identification success rate at the species level was increased to 85%. The possibility of direct biofilm analysis was also examined by testing four sample preparation procedures; however, identification of beer contaminants was not successful, as protein signals needed for microorganism identification were not detected by this approach. MALDI-TOF MS including the cultivation step in connection with a reference database containing relevant entries was found as a suitable method for identification of contaminants from brewery environment.

We investigated the incidence and species distribution of Pectinatus species in brewery bottling halls. A total of 11 bottling lines in 10 different brewery plants were screened for the presence of...

A modified de Man–Rogosa–Sharpe (MRS) medium suitable for easy, fast, and specific detection of beer-spoilage bacteria Pectinatus spp. from beer and brewery swab samples was developed. It contains ...

Potamogeton filiformis, P. pectinatus and P. vaginatus are three closely related species that produce sterile hybrids. These hybrids can be extremely difficult to identify, especially if in a vegetative state. To solve this problem, a protocol involving restriction fragment length polymorphism analysis of internal transcribed spacer rDNA is described that allows all three species and their hybrids to be distinguished. Analysis of internal transcribed spacer sequences shows that P. filiformis is closely related to P. vaginatus (differing by only a single substitution), whereas P. pectinatus differs from both by three indels and at least 20 substitutions. Infra-specific sequence variation was seen only in P. pectinatus, in which material from arctic Russia differed from that from Scotland, the Nordic region, the Netherlands and Italy by seven mutations.

Multiplex PCR methods were developed to detect 12 species of beer-spoilage bacteria that belong to the genera Lactobacillus, Pectinatus, Pediococcus, and Megasphaera. For microbiological quality control in breweries, we divided these species into three groups and evaluated a multiplex PCR method to simultaneously detect beer-spoilage species belonging to each group. Subsequently, the primer designs and blending ratios for each multiplex PCR analysis were optimized to satisfy the performance required for practical applications by breweries. As a result, each PCR method showed sufficient specificity to the target species and exhibited identical sensitivity with corresponding species-specific simplex PCR methods. In addition, none of the three multiplex methods showed a false-positive reaction to the nonspoilage bacterial strains frequently detected in breweries. Furthermore, artificial positive control DNAs were designed from λ-phage genomic DNA sequences to assure the performance of the PCR tests. Consequently, only one PCR test tube was required to ensure that all primer pairs in a multiplex PCR method were fully functional, instead of using multiple test tubes for separate confirmation of the respective primer pairs. Taken together, these multiplex PCR analyses enabled us to reliably and comprehensively detect beer-spoilage bacteria more easily and inexpensively.

Summary The complete larval development of Pagurus pectinatus is described based on laboratory rearing. The species has four zoeal stages and a megalopa. The larvae are described and illustrated, and detailed comparisons are made with other pagurid larvae in closely related species. Adults of P. pectinatus have been misidentified with those of Pagurus brachiomastus and Pagurus kennerlyi. However, larvae of P. pectinatus show morphological differences to those of other similar species in the shape of the carapace and the setal formulae of the appendages.

The monospecific genus Ageleodus is a primitive chondrichthyan known exclusively from isolated Late Devonian and Carboniferous teeth. Due in part to the paucity of material, dental variation in Ageleo dus has not been fully recognized. This paper reports on a large new sample of Ageleodus pectinatus teeth (382) from the Catskill Formation (Late Devonian, late Famennian) at the Red Hill site in Clinton County, Pennsylvania, U.S.A. It represents the earliest recorded occurrence of the genus, and the largest catalogued sample of A. pectinatus from a single site. This sample allows for a thorough description of morpho logical variation within A. pectinatus teeth and gives occasion to a re view of the species' nomenclatural history. Nomenclatural History Agassiz (1838) described three species of Ctenoptychius (C. apicalis Agassiz, 1838; C. denticulatus Agassiz, 1838; and C. pectinatus Ag assiz, 1838) from isolated teeth. The type material of C. apicalis is from the Late Carboniferous (Westphalian) of Staffordshire, England. The type material of C. denticulatus and C. pectinatus is from the Burdie House Limestone (Early Carboniferous, Visean) of Scotland. Agassiz' original specimens are missing (Susan Turner, pers. comm.); the rele vant illustrations from Agassiz' (1838) plate are reproduced here in Figure 1. The original specimen of C. apicalis (Fig. 1A) has a short root and a raised, medially-acuminate crown with imbricated basal ridg es. Conical cusps divide the arching coronal margin. The prominent central cusp is bordered by three to four smaller cusps that decrease in size mesially and distally. (Note: because the arrangement of teeth with in the mouth of Ageleodus is unknown, in the present paper, the terms mesial and distal [sensu Peyer, 1968] refer to direction along the long horizontal axis or length of the tooth; lingual and labial refer to direction along the short axis or width of the tooth.) Two of the three original specimens of C. pectinatus (Fig. IB, C) exhibit a tall root punctured with nutritive foramina and a raised crown. The coronal margin is straight to slightly arched and is divided into nine or fewer cusps. The third specimen ascribed to C. pectinatus (Fig. ID) has a very different morphology and, under present consideration, does not belong to either Ctenoptychius or Ageleodus. This tooth has a raised crown and short root. The tightly arched coronal margin is divided into bulbous cusps. Cusp size decreases with proximity to the mesial and distal edges of the tooth. The original C denticulatus specimens (Fig. 1E-G) exhibit a tall root punctured with nutritive foramina and a raised crown. Four teen or more slender cusps of equal dimensions divide the coronal mar gin.

A laboratory growth experiment indicated that the ribbon-leaved Potamogeton gramineus L. had a lower light compensation point for growth (LCP) than the thread-leaved P. pectinatus L. LCP and 95 % confidence intervals (CI) were 0.86 M m−2 day−1 (95% CI, −0.006 to 1.540) and 3.87 M m−2 day−1 (95% CI, 3.12 to 4.63), respectively. When germinated propagules of each species were planted in a P. gramineus stand in the Byrnes Canal, P. pectinatus exhibited lower survival than similar plants placed in the canal but outside the P. gramineus bed. Mean plant weight for P. pectinatus grown within the plant bed was less than 10 % of that for plants grown outside the P. gramineus bed. Neither survival nor mean dry weight of P. gramineus planted at the same sites differed among the sites. Estimates of light levels in the P. gramineus bed indicated that shading by P. gramineus reduced light to levels at or below the LCP for P. pectinatus but above the LCP for P. gramineus. These results suggest that P. pectinatu...

A fluorescent in situ hybridization (FISH) technique, based on binding of a fluorescein-labelled oligonucleotide probe to rRNA, was used to determine a viable population of bacteria. We designed the oligonucleotide probes targeted to 16S rRNA of anaerobic beer-spoilage bacteria belonging to the genus Pectinatus and assessed the sensitivity and specificity of the FISH method using the bacteria spiked into beer. The FISH technique could be applied directly to the beer samples without a culturing step, which typically requires several days. This method was able to detect beer-spoilage bacteria in a species-specific manner within 5 hr. In addition, we developed another useful application of the FISH, a quantitative method using an internal control for enumeration. La technique d'hybridation moleculaire in situ avec sonde fluorescente (FISH) est utilisee pour determiner une population bacterienne viable. Des sondes oligonucleotidiques fluorescentes specifiques des RNA ribosomiques 16S de la bacterie anaerobie alterant la biere Pectinatus ont ete synthetisees et testees. La methode peut etre utilisee directement sur la biere, la detection se fait en 5 heures.

A total of 39 Pectinatus strains have been ribotyped in this investigation. Thirteen different ribotypes were observed from 34 strains of P. frisingensis, while three different types were shown with five strains of P. cerevisiiphilus when digested with EcoRI. These patterns consisted of two series of fragments: fragments conserved within a species, and polymorphic variation. P frisingensis had conserved fragments of 2.5-3, 7-8, and 10-20 kbp, whereas P. cerevisiiphilus had 2-3, 5-6, and 20-30 kbp. These fragment patterns, characterized by sets of conserved fragments within a species, were species specific. Furthermore, the HindIII- and BamHI-digested restriction patterns have been examined to facilitate differentiation at the strain level. Thirty-four strains of P. frisingensis could be divided into 1 of 12 types. On the other hand a composite ribotype, which combined the ribotypes produced by all restriction enzymes used, produced such high definition that all strains of P. frisingensis fell into 1 of 17 types.

We examined the potential allelopathic effect of American lotus (Nelumbo lutea) on two submerged plant species common to Great Lakes coastal wetlands: Eurasian watermilfoil (Myriophyllum spicatum) and sago pondweed (Potamogeton pectinatus). Whole N. lutea seedlings and aqueous leaf extracts were employed as sources of putative allelochemical agents. N. lutea seedlings had no effect on the growth of target plants over seven-day exposures. Aqueous extracts at both 2% and 10% titers significantly stimulated (P < 0.05) shoot growth rates in M. spicatum compared with extract-free control plants. N. lutea extracts were ineffective in altering P. pectinatus growth rates. These findings suggest that, at natural plant population densities, it is unlikely that N. lutea allelopathy plays a significant role in watermilfoil or sago pondweed population dynamics.

The effect of sediment composition on the growth of Potamogeton pectinatus and Myriophyllum spicatum was evaluated by a greenhouse experiment in which segments of both species were grown on 37 sediments, which ranged from highly flocculent to sandy, collected from the calcareous, shallow eutrophic Lake Krankesjon. The two species responded similarly to the 37 sediment types; there was a strong correlation between the final biomass of M. spicatum and the final biomass of P. pectinatus for a given sediment type. Our results indicated that in these sediments, organic matter and density were not effective predictors of macrophyte growth. Root:shoot ratios of both P. pectinatus and M. spicatum were inversely related to the final biomass, and phosphorus and nitrogen concentrations of M. spicatum shoots were inversely related to root:shoot ratios. This suggests that plants were responding to sediment infertility by allocating proportionately more growth to root formation. Tissue analysis indicated that ...

A selective medium for the isolation of Megasphaera and Pectinatus, designated “SMMP,” was developed. The basal medium contained lactate, which served as the sole source of carbon, and reducing age...

Potamogeton pectinatus L., grown in greenhouse cultures, was harvested from three photoperiod treatments (16 h, 10 h, and 16 h switched to 10 h after four weeks) at weekly intervals. Plant weight increased over time, and those plants grown at a 16 h photoperiod showed the greatest increase. Plants began to produce tubers after 70 to 77 days at all photoperiods. Plants grown at the 16 h photoperiod and those initially grown at 16 h and switched to the 10 h photoperiod allocated less biomass to new tubers (ca. 5%) than those grown at the 10 h photoperiod (ca. 30%). Plants grown at the 10 h photoperiod had decreased weights of stems and leaves. Plants grown at the long photoperiod produced tubers after attaining dry weights between 0.8 and 1.0 g. Plants grown at the short photoperiods produced tubers regardless of plant weight, but the frequency of tuber production increased for larger plants. Changes in the pigment and protein content of leaves were not associated with the onset of tuber production.

Rhytidothorax Ashmead is reported for the first time from India. Two new species, R. nigrum and R. pectinatus are described from Assam. A key to the world species is given.

Some species of lactobacilli are known to be serious beer-spoilage bacteria. Therefore, there have been several reports about detection of beer-spoilage Lactobacillus spp. (4,9-13,15). In addition to species discrimination, strain typing has been necessary for epidemiological study. Ribotyping is one method of strain typing and is used for the characterization of the restriction fragment length polymorphism. Furthermore, this method has proved to be a useful molecular epidemiological technique (1). There have been several reports about ribotyping of a number of pathogens, such as Listeria monocytogenes (2,14), Vibrio anguillarum (7), and V. cholerae (3). Previously, we reported the application of this molecular-typing for the beer-spoilage bacteria Pectinatus spp. (6). There have also been some reports about ribotyping of Lactobacillus spp. (5,8,10,16). However, little attention has been given to whether ribotyping can be used to discriminate between species and subspecies. In this study, we attempt to establish ribotypes of beer-spoilage Lactobacillus spp., and whether ribotyping of Lactobacillus spp. can be used for species-subspecies discrimination and epidemiological study.

Early growth of Potamoaeton gramineus L. was evaluated at several combinations of temperature (10 to 35 C) and light (7 to 213 umol m−2 s−1) in laboratory cultures. Leaf production rates were positive except at 35 C, and generally increased at higher light levels. Leaf production was reduced at 10 or 35 C. At low light levels ( 65 umol m−2 s−1) dry weight increased and appeared to be a function of temperature. At ≥ 65 umol m−2 s−1 P. gramineus was photosynthetically sufficient within 4 weeks of sprouting. Comparison of P. gramineus and P. pectinatus showed that P. gramineus would not grow as rapidly under early season conditions.

The GC technique described here, including the extraction technique, the column selection, and operating conditions, has been modified to provide a specific and simple tool for the identification a...

Results from experiments with Potamogeton pectinatus L. grown in an artificial substrate amended with various combinations of peat and glucose or sucrose suggest that plant weight and the number and weight of tubers produced per plant increased significantly when plants were grown in sediment amended with peat. Contrary to expectations, the addition of labile organic components, glucose or sucrose, to the substrate (up to 15%, w/w) did not influence plant growth. Plants grown in sediment amended with peat had higher levels of tissue Fe. The weight of tubers produced per gram of non tuber tissue was not influenced by sediment properties. These results support the hypothesis that the mechanism by which sediment organic matter affects macrophyte growth is by altering sediment density.

The water-distilled essential oil of Thymus pectinatus Fisch. et Mey. var. pectinatus was studied by GC/MS. Fifty-six compounds representing 96.14% of the oil were characterized. Major constituents of the oil were thymol (35%), borneol (17.70%) and p-cymene (11.12%).

Until recently, gram-negative bacteria have not been considered to be common spoilers of finished (packaged) beer. In this article, however, two gram-negative, obligately anaerobic, beer spoilers o...

27 species of Harpacticoida are reported from 7 samples from muddy bottoms at different depths in the fjords near Bergen. Tetragoniceps bergensis and Mesocletodes robustus are new species, while Apodella crassa gen. et sp. n. justifies the creation of a new genus. Ceratonotus pectinatus elaphus is a new subspecies. All the other species have been previously reported from North Atlantic waters but new morphological data are added about some of them. A few comparative ecological conclusions are given.

(1936). The Anatomy of Potamogeton Pectinatus. Transactions of the Botanical Society of Edinburgh: Vol. 32, No. 1, pp. 179-186.

SUMMARY The absorption and release of 32PO4, by Potamogeton pectinatus L during winter was investigated using a partitioned container in which the roots were separated from the stems and leaves. 32PO4 is absorbed by the roots as well as the stems and leaves under both light and dark conditions and transported to all parts of the plant. Transport rates (μg P plant−1 24 hr−1) show that more phosphorus is released by the roots than by the stems and leaves, indicating a nett movement of phosphorus from the surrounding water to the substrate. Foliar absorption of 32P exceeds root absorption under both light and dark conditions.

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