Insect awards

The next draft of the information sheet to accompany New Zealand native insect display case is finished, except for photos.  Images have to come from Landcare Resource's database for copyright reasons, and some of the photos I had selected were from other databases. LandCare has vast catalogues, but specimens numerically, not by name, which made it difficult for me to be certain that I had selected the correct photo.  Sarah will help me with this.  

It was decided the make up the display cases for school in themes -  I entitled this one 'The Inaugural Insect Awards' as each specimen was chosen for a specific reason: the longest, heaviest, stinkiest, noisiest, brightest, and so on.

I visited Science Club at Cockle Bay as the guest speaker.  After looking at some display cases, students decided what themes they would be interested in for insect displays:

I will take this information back to Landcare and work on some more themed displays!

Kauri die back in the media

Kauri die back disease is in the media, with newspaper articles about the closing of walking tracks in the Waitakere Ranges.

Checking Kombucha sub cultures

By Day 3,  all the subcultures of Kombucha showed some evidence of growth, some more than others.  The cultures growing on BHI were the slowest growing. 

After some instruction, I took photos of all the subcultures and kept a record of photos digitally.

The camera was a very sophisticated piece of equipment.

When recording growth, the convention is that the day when cultures are plated is Day 0, then numerically after that.  Days can be recorded as a minus number to indicate the days of preparation before plating, eg when making and concentrating liquid culture before plating.

Kombucha project

Megan has tasked me with isolating the bacteria in three samples of Kombucha, one bought in New Zealand, one from Australia and one from the drink itself.  Under her direction, I plated the three samples of five different media: half PDA, brain, heart infusion (BHI), chocolate (horse blood medium),  Kings Bee and AC.  

On Day 4, after the weekend, I looked to see what colonies were starting to form in which medium.
Some sample plates:

Under Megan's guidance, I make subcultures of 'interesting looking' colonies, ie those that were more likely to be bacteria rather than yeast.  It was a case of looking for the unusual, ones that were not too glossy like yeast.   I prepared plates with 3 or 4 unusual looking subcultures (from the same medium) on the same plate, to make efficient use of the media available.   These cultures are being incubated at 25 degrees C.  

I am relishing having a project to manage, with Megan available to answer questions and guide me when necessary.  It is making me feel more directly involved, and accelerating my learning about what it feels like to be a scientist.  I am learning about lab procedures and the methodical recording of data but more importantly, the wider picture of being a scientist - starting with a question - do we know what it is Kombucha? Could some of the bacteria be new to New Zealand?  How came we find out?  What scientific investigations do I need to conduct?  How will I record my data? What are the ramifications of this investigation?  It is authentic hands-on science, as opposed to observational science, and I am very excited to be involved.

Introducing Kombucha

Kombucha is a fermented tea made from SCOBY - Symbiotic Colony of Bacteria and Yeast.  Megan is endeavouring to isolate the bacteria to ascertain that there are no strains of bacteria present that are new to New Zealand.  It is proving difficult to isolate the bacteria as the yeast is so abundant in the cultures.  

Megan showed me the yeast and bacteria on slides. she had prepared.

Inhibition assays

I prepared inhibition assays for the kauri die-back project by taking little plugs of the fungal subcultures, two at a time,  so that they oppose each other on the petri dish.  This is a way to observe which fungus grows the strongest and thus inhibits the other's growth.  Over time, it will provide valuable data as scientists work towards a potential biocontrol of the disease.

Instructions from Marj written in my notebook as diagrams for clarity.

It is necessary to work in the PC2 hood when working on Q cultures.  It has a 20 minute cycle of ultra violet light to sterilise surfaces before and after work is carried out.

Sub cultures in liquid media

Sub cultures of the fungi used in the kauri die back project - Trichoderma, Illyonectra and Fortini, and Agathidicida - were dropped into flasks of PDB and allowed to grow.  They were incubated at 20 degrees on the 'juggler'  ( a device that keeps flasks moving in a constant smooth fashion).  To give them sufficient time to incubate, Marg instructed me to check on them in about a week.

After four days, you can see the cloudiness indicating fungal growth.

Some cultures grow more slowly, and need more time.

ICMP

The International Collection of Microorganisms from Plants (ICMP) is located at Landcare Resource's Auckland regional office.  It is a major international collection of living cultures of plant associated bacteria and fungi from New Zealand, and from overseas as well.  There are over 20,000 strains of bacteria and fungi from plants and soil.  Megan is the collection manager.

Cultures are stored in liquid nitrogen at minus 196 degrees C by a process known as crypopreservation.

Elsa is depositing more specimens into the collection.

A methodical record of deposits and dispatches are kept in the lab.  to check that specimens remain viable, from time to time, Rose takes out culture and plates it to see that it incubates.  Scientists from all over the world request cultures, not just scientists from New Zealand.

Fungal cultures are stored in drinking straws! I sometimes cut plastic straws into 4cm lengths and seal the ends on this heat activated press to make storage units.

Cultures sealed in plastic straw cases and ready to be sterilised before storage in the ICMP collection.

Making PDA (gel) media

Potato Dextrose Agar (PDA) is made in a similar way,  mixed and sterilised in the autoclave; but then it is poured into petri dishes and left to set. 

As a guide, you can pour twenty plates from 500ml of PDA.  If you pour more plates, it means that the layer of nutrient is too thin and that there will not be enough food for the plated bacteria.  I am getting better at judging this, but my first pour produces nearly 30 rather meagre plates.

I

Making liquid media

The fungal subcultures for the kauri die back need to be grown in liquid culture, so first I had to make Potato Detrose Broth.  This has the same nutritional content as Potato Dextrose Agar (PDA) but is in a different form.

I use my lab notebook to write down exactly what I have to do, so that I have a reference for later and can look things up, a little like CBS Maths modelling books

You need to mix up the liquid media very thoroughly.

Pouring the liquid media into flasks.

The media must be sterilised in the autoclave.  As a check, the stripes of the tape go black after being autoclaved.

Easter at Landcare

The office staff arranged an Easter morning tea and chocolate treats for the staff everyone appreciated the kind gesture and made an effort to attend.

Over Easter, we drove up to Northland and paid our respects to Tane Mahuta in the Waipoua Kauri Forest.  It was gratifying to see visitors taking the cleaning procedures seriously and cleaning their footwear thoroughly.

This article was in the New Zealand Herald - kauri die back and the precautions the public can make
is increasingly in the media.