Primjena replika tehnike u istraživanjima fizioloških grupa bakterija u površinskim vodama

The method of replica technique is a new way of determining the presence of physiological groups of bacteria in surface waters. By using the method of replica technique it was established that the percentage of proteolytic and phosphomineralizing bacteria decreased, in relation to the number of saprophytic bacteria on MPA, at the places of the greatest pollution of the river Sava, while at the same time the percentage of amylo- lytic and especially of phosphomobilizing bacteria increased. The same method was used in examining the influence of temperature on the proteolytic activity of the bacterial strains from river Sava, and it was established that the highest number of bacteria on MPA hydrolyzed gelatine between 22° C and 26° C. A special advantage of the replica technique method in hydromicrobiology is in the minimal use of laboratory material and in time saving, and it is possible to work out a relatively great number of samples at the same time. The reported method is very simple and feasible in all laboratories.U ovom su radu kao nov pristup istraživanjima ekologije fizioloških grupa bakterija u površinskim vodama, iznijeti neki rezultati dobiveni vlastitom modifikacijom replika tehnike (Lederberg and Lederberg 1952). Ispitivana je zastupljenost proteolitičkih bakterija, fosfomineralizatora, fos- fomobilizatora i amilolitičkih bakterija unutar populacija saprofitnih bakterija izoliranih na MPA (mesno-peptonski agar) iz savske vode nizvodno od Zagreba (Ščitarjevo — Galdovo) u mjesecu studenom 1978. Najveći broj bakterija svih grupa nađen je kod Dubrovčaka, što je posljedica zagađenosti Save otpadnim vodama Zagreba nizvodno od Ščitarjeva (fig. 2), na što upućuju i neki hidrokemijski parametri (tab. 1). Nizvodno od Dubrovčaka opada broj saprofita i bakterija ispitivanih grupa, što je znak autopurifikacije rijeke, pa kod Galdova dobivamo u vrijeme istraživanja bakteriološku sliku sličnu onoj kod Ščitarjeva prije ulijevanja kolektora grada. Metodom replika tehnike moglo se utvrditi da se obzirom na opterećenost rijeke dolazi do promjena odnosa među pojedinim fiziološkim grupama s obzirom na broj saprofitnih bakterija. Tako u manje opterećenim dijelovima rijeke najveći udio u populacijama saprofita na MPA imaju proteolitički sojevi i nešto manje fosfomobilizatori, dok su u jače zagađenim apsolutno dominantni samo fosfomobilizatori (fig. 3). Metodom replika tehnike mogu se u hiđromikrobiologiji relativno brzo dobiti podaci o utjecaju raznovrsnih ekoloških faktora na aktivnost bakterija. Ispitivanjem utjecaja temperature na proteolitičku aktivnost sojeva iz savske vode moglo se u roku od 24 sata konstatirati da najveći broj saprofitnih bakterija na MPA sa želatinom pokazuje hidrolitičku aktivnost od 22° C do 26° C. Primjenom replika tehnike u istraživanjima fizioloških grupa bakterija postiže se minimalna potrošnja laboratorijskog posuđa i hranjivih podloga, jer je potrebno dobiti samo kolonije saprofitnih bakterija u povoljnom razređenju na MPA (radi daljeg repliciran ja), a to je i inače rutinska pretraga voda u svakom mikrobiološkom laboratoriju. Takođe se postiže velika ušteda u vremenu, što omogućuje ispitivanje većeg broja uzoraka odjedanput. Posebno je važno to da se opisana metoda može zbog svoje jednostavnosti i lagane tehničke izvedbe primijeniti u svakom hidro- mikrobiološkom laboratoriju

Što treba znati o hrvatskoj kemijskoj nomenklaturi?

Načinjen je pregled najčešćih pogrešaka i zabluda vezanih uz hrvatsku kemijsku nomenklaturu. Objašnjena je razlika između nomenklature i nazivlja. Za kemijske elemente selenij, telurij, titanij i uranij ne bi trebalo rabiti zastarjela imena selen, telur, titan i uran. Jedan kemijski spoj može imati više ispravnih kemijskih imena. Treba razlikovati posvojne pridjeve izvedene iz imenâ kemijskih elemenata (npr. ugljikov, aluminijev, platinin) od gradivnih pridjeva izvedenih iz imenâ njihovih elementarnih tvari (npr. ugljični, aluminijski, platinski). Pri pisanju kemijskih imena treba paziti na pravila o uporabi razmaka i spojnice, a treba voditi računa i o pravilnoj uporabi kurziva. U hrvatskom jeziku prefiksi koji u supstitucijskoj nomenklaturi označuju halogene supstituente nisu identični prefiksima koji u koordinacijskoj nomenklaturi označuju halogene ligande

Plate method for counting proteolytic sulphide-producing bacteria

The proteolytic sulphide-producing bacteria (PSPB) are widely distributed in water and sediment and are a good indicator of the ecological status of ecosystems. From the ecological point of view it is important to distinguish the physiological group of PSPB from other bacteria producing H2S from sulphate, sulphite or thiosulphate. A new medium named peptone-cysteine-ammonium iron citrate agar (PCA) was developed and tested. The medium regularly gave a higher number of colony forming units than the control media for detection of sulphide formation, indole production and motility (Merck) and iron sulphite agar (Oxoid). For the enumeration of PSPB from the environment, the simultaneous incubation of samples in aerobic and anaerobic conditions is recommended and a higher number should be taken for interpretation

Nutrient removal from leachate of the Zagreb landfill Jakusevec

Remediation of the City of Zagreb Jakuševec Dump Site, one of the largest dump sites in Europe, is in progress. Experimental laboratory results of leachate treatment using aquatic macrophytes show that increasing the concentration of ammonia in the leachate decreases elimination efficiency. In all series of experiments, significantly greater elimination of ammonia and orthophosphates has been obtained in planted than in unplanted mesocosms. For polishing the effluent from the pilot constructed wetland in the polishing pond the following species might be recommended: Phragmites australis, Myriophyllum verticilatum, Ceratophyllum demersum, Lemna minor and Salvinia natans

Mapping the realms of the soldiers: cartographies of military landscapes in Skopje and Bitola

This paper presents the process and the results of a cartographic exploration on the interactions between the military and the civil society. It features two interrelated study-cases : the cities of Skopje and Bitola, both characterised by consequent periods of war and strong army presence. Frequent and often abrupt changes of occupying military power combined with the local effects of ever-evolving military strategy, altogether having a dramatic impact upon their urban landscapes and the overall territorial settings. The proposed method of exploration includes the study and processing of archival sources as well as the creation of novel interpretative maps. The former includes a critical analysis of historical and contemporary cartographies, taking into account the specific agency of mapping and its embedded politics. As for the later, two series of eight maps each are created, offering a diachronic as well as a synchronic reading of the history of the local militarised landscapes. Through the simultaneous deconstruction of archival maps and the construction of interpretative maps, the research approaches the interaction of the military and the city in a twofold way: on the one hand revealing process of appropriation through the act of mapping -in which the specific agency of the military plays a significant role, and on the other hand constructing a palimpsests of urban and territorial army-related narratives that enables the formation and transmission of the city's memory.Peer Reviewe